5 Easy Steps to Multiply and Divide Fractions

5 Easy Steps to Multiply and Divide Fractions

In the realm of mathematics, fractions play a pivotal role, providing a means to represent parts of wholes and enabling us to perform various calculations with ease. When faced with the task of multiplying or dividing fractions, many individuals may experience a sense of apprehension. However, by breaking down these operations into manageable steps, we can unlock the secrets of fraction manipulation and conquer any mathematical challenge that comes our way.

To begin our journey, let us first consider the process of multiplying fractions. When multiplying two fractions, we simply multiply the numerators and the denominators of the two fractions. For instance, if we have the fractions 1/2 and 2/3, we multiply 1 by 2 and 2 by 3 to obtain 2/6. This result can then be simplified to 1/3 by dividing both the numerator and the denominator by 2. By following this simple procedure, we can efficiently multiply any two fractions.

Next, let us turn our attention to the operation of dividing fractions. Unlike multiplication, which involves multiplying both numerators and denominators, division of fractions requires us to invert the second fraction and then multiply. For example, if we have the fractions 1/2 and 2/3, we invert 2/3 to obtain 3/2 and then multiply 1/2 by 3/2. This results in 3/4. By understanding this fundamental rule, we can confidently tackle any division of fraction problem that we may encounter.

Understanding the Concept of Fractions

Fractions are a mathematical concept that represent parts of a whole. They are written as two numbers separated by a line, with the top number (the numerator) indicating the number of parts being considered, and the bottom number (the denominator) indicating the total number of equal parts that make up the whole.

For example, the fraction 1/2 represents one half of a whole, meaning that it is divided into two equal parts and one of those parts is being considered. Similarly, the fraction 3/4 represents three-fourths of a whole, indicating that the whole is divided into four equal parts and three of those parts are being considered.

Fractions can be used to represent various concepts in mathematics and everyday life, such as proportions, ratios, percentages, and measurements. They allow us to express quantities that are not whole numbers and to perform operations like addition, subtraction, multiplication, and division involving such quantities.

Fraction Meaning
1/2 One half of a whole
3/4 Three-fourths of a whole
5/8 Five-eighths of a whole
7/10 Seven-tenths of a whole

Multiplying Fractions with Whole Numbers

Multiplying fractions with whole numbers is a relatively straightforward process. To do this, simply multiply the numerator of the fraction by the whole number, and then keep the same denominator.

For example, to multiply 1/2 by 3, we would do the following:

“`
1/2 * 3 = (1 * 3) / 2 = 3/2
“`

In this example, we multiplied the numerator of the fraction (1) by the whole number (3), and then kept the same denominator (2). The result is the fraction 3/2.

However, it is important to note that when multiplying mixed numbers with whole numbers, we must first convert the mixed number to an improper fraction. To do this, we multiply the whole number part of the mixed number by the denominator of the fraction, and then add the numerator of the fraction. The result is the numerator of the improper fraction, and the denominator remains the same.

For example, to convert the mixed number 1 1/2 to an improper fraction, we would do the following:

“`
1 1/2 = (1 * 2) + 1/2 = 3/2
“`

Once we have converted the mixed number to an improper fraction, we can then multiply it by the whole number as usual.

Here is a table summarizing the steps for multiplying fractions with whole numbers:

Step Description
1 Convert any mixed numbers to improper fractions.
2 Multiply the numerator of the fraction by the whole number.
3 Keep the same denominator.

Multiplying Fractions with Fractions

Multiplying fractions with fractions is a simple process that can be broken down into three steps:

Step 1: Multiply the numerators

The first step is to multiply the numerators of the two fractions. The numerator is the number on top of the fraction.

For example, if we want to multiply 1/2 by 3/4, we would multiply 1 by 3 to get 3. This would be the numerator of the answer.

Step 2: Multiply the denominators

The second step is to multiply the denominators of the two fractions. The denominator is the number on the bottom of the fraction.

For example, if we want to multiply 1/2 by 3/4, we would multiply 2 by 4 to get 8. This would be the denominator of the answer.

Step 3: Simplify the answer

The third step is to simplify the answer by dividing the numerator and denominator by any common factors.

For example, if we want to simplify 3/8, we would divide both the numerator and denominator by 3 to get 1/2.

Here is a table that summarizes the steps for multiplying fractions with fractions:

Step Description
1 Multiply the numerators.
2 Multiply the denominators.
3 Simplify the answer by dividing the numerator and denominator by any common factors.

Dividing Fractions by Whole Numbers

Dividing fractions by whole numbers can be simplified by converting the whole number into a fraction with a denominator of 1.

Here’s how it works:

  1. Step 1: Convert the whole number to a fraction.

    To do this, add 1 as the denominator of the whole number. For example, the whole number 3 becomes the fraction 3/1.

  2. Step 2: Divide fractions.

    Divide the fraction by the whole number, which is now a fraction. To divide fractions, invert the second fraction (the one you’re dividing by) and multiply it by the first fraction.

  3. Step 3: Simplify the result.

    Simplify the resulting fraction by dividing the numerator and denominator by any common factors.

For example, to divide the fraction 1/4 by the whole number 2:

  1. Convert 2 to a fraction: 2/1
  2. Invert and multiply: 1/4 ÷ 2/1 = 1/4 × 1/2 = 1/8
  3. Simplify the result: 1/8
Conversion 1/1
Division 1/4 ÷ 2/1 = 1/4 × 1/2
Simplified 1/8

Dividing Fractions by Fractions

When dividing fractions by fractions, the process is similar to multiplying fractions, except that you flip the divisor fraction (the one that is dividing) and multiply. Instead of multiplying the numerators and denominators of the dividend and divisor, you multiply the numerator of the dividend by the denominator of the divisor, and the denominator of the dividend by the numerator of the divisor.

Example

Divide 2/3 by 1/2:

(2/3) ÷ (1/2) = (2/3) x (2/1) = 4/3

Rules for Dividing Fractions:

  1. Flip the divisor fraction.
  2. Multiply the dividend by the flipped divisor.

Tips

  • Simplify both the dividend and divisor if possible before dividing.
  • Remember to flip the divisor fraction, not the dividend.
  • Reduce the answer to its simplest form, if necessary.

Dividing Mixed Numbers

To divide mixed numbers, convert them to improper fractions first. Then, follow the steps above to divide the fractions.

Example

Divide 3 1/2 by 1 1/4:

Convert 3 1/2 to an improper fraction: (3 x 2) + 1 = 7/2
Convert 1 1/4 to an improper fraction: (1 x 4) + 1 = 5/4

(7/2) ÷ (5/4) = (7/2) x (4/5) = 14/5

Dividend Divisor Result
2/3 1/2 4/3
3 1/2 1 1/4 14/5

Simplifying Fractions before Multiplication or Division

Simplifying fractions is an important step before performing multiplication or division operations. Here’s a step-by-step guide:

1. Find Common Denominator

To find a common denominator for two fractions, multiply the numerator of the first fraction by the denominator of the second fraction, and vice versa. The result will be the numerator of the new fraction. Multiply the original denominators to get the denominator of the new fraction.

2. Simplify Numerator and Denominator

If the new numerator and denominator have common factors, simplify the fraction by dividing both by the greatest common factor (GCF).

3. Check for Improper Fractions

If the numerator of the simplified fraction is greater than or equal to the denominator, it is considered an improper fraction. Convert improper fractions to mixed numbers by dividing the numerator by the denominator and keeping the remainder as the fraction.

4. Simplify Mixed Numbers

If the mixed number has a fraction part, simplify the fraction by finding its simplest form.

5. Convert Mixed Numbers to Improper Fractions

If necessary, convert mixed numbers back to improper fractions by multiplying the whole number by the denominator and adding the numerator. This is required for performing division operations.

6. Example

Let’s simplify the fraction 2/3 and multiply it by 3/4.

Step Operation Simplified Fraction
1 Find common denominator 2×43×4=812
2 Simplify numerator and denominator 812=8÷412÷4=23
3 Multiply fractions 23×34=2×33×4=12

Therefore, the simplified product of 2/3 and 3/4 is 1/2.

Finding Common Denominators

Finding a common denominator involves identifying the least common multiple (LCM) of the denominators of the fractions involved. The LCM is the smallest number that is divisible by all the denominators without leaving a remainder.

To find the common denominator:

  1. List all the factors of each denominator.
  2. Identify the common factors and select the greatest one.
  3. Multiply the remaining factors from each denominator with the greatest common factor.
  4. The resulting number is the common denominator.

Example:

Find the common denominator of 1/2, 1/3, and 1/6.

Factors of 2 Factors of 3 Factors of 6
1, 2 1, 3 1, 2, 3, 6

The greatest common factor is 1, and the only remaining factor from 6 is 2.

Common denominator = 1 * 2 = 2

Therefore, the common denominator of 1/2, 1/3, and 1/6 is 2.

Using Reciprocals for Division

When dividing fractions, we can use a trick called “reciprocals.” The reciprocal of a fraction is simply the fraction flipped upside down. For example, the reciprocal of 1/2 is 2/1.

To divide fractions using reciprocals, we simply multiply the dividend (the fraction we’re dividing) by the reciprocal of the divisor (the fraction we’re dividing by). For example, to divide 1/2 by 1/4, we would multiply 1/2 by 4/1:

“`
1/2 x 4/1 = 4/2 = 2
“`

This trick makes dividing fractions much easier. Here are some examples to practice:

Dividend Divisor Reciprocal of Divisor Product Simplified Product
1/2 1/4 4/1 4/2 2
3/4 1/3 3/1 9/4 9/4
5/6 2/3 3/2 15/12 5/4

As you can see, using reciprocals makes dividing fractions much easier! Just remember to always flip the divisor upside down before multiplying.

Mixed Fractions and Improper Fractions

Mixed fractions are made up of a whole number and a fraction, e.g., 2 1/2. Improper fractions are fractions that have a numerator greater than or equal to the denominator, e.g., 5/2.

Converting Mixed Fractions to Improper Fractions

To convert a mixed fraction to an improper fraction, multiply the whole number by the denominator and add the numerator. The result becomes the new numerator, and the denominator remains the same.

Example

Convert 2 1/2 to an improper fraction:

2 × 2 + 1 = 5

Therefore, 2 1/2 = 5/2.

Converting Improper Fractions to Mixed Fractions

To convert an improper fraction to a mixed fraction, divide the numerator by the denominator. The quotient is the whole number, and the remainder becomes the numerator of the fraction. The denominator remains the same.

Example

Convert 5/2 to a mixed fraction:

5 ÷ 2 = 2 R 1

Therefore, 5/2 = 2 1/2.

Using Visual Aids and Examples

Visual aids and examples can make it easier to understand how to multiply and divide fractions. Here are some examples:

Multiplication

Example 1

To multiply the fraction 1/2 by 3, you can draw a rectangle that is 1 unit wide and 2 units high. Divide the rectangle into 2 equal parts horizontally. Then, divide each of those parts into 3 equal parts vertically. This will create 6 equal parts in total.

The area of each part is 1/6, so the total area of the rectangle is 6 * 1/6 = 1.

Example 2

To multiply the fraction 3/4 by 2, you can draw a rectangle that is 3 units wide and 4 units high. Divide the rectangle into 4 equal parts horizontally. Then, divide each of those parts into 2 equal parts vertically. This will create 8 equal parts in total.

The area of each part is 3/8, so the total area of the rectangle is 8 * 3/8 = 3/2.

Division

Example 1

To divide the fraction 1/2 by 3, you can draw a rectangle that is 1 unit wide and 2 units high. Divide the rectangle into 2 equal parts horizontally. Then, divide each of those parts into 3 equal parts vertically. This will create 6 equal parts in total.

Each part represents 1/6 of the whole rectangle. So, 1/2 divided by 3 is equal to 1/6.

Example 2

To divide the fraction 3/4 by 2, you can draw a rectangle that is 3 units wide and 4 units high. Divide the rectangle into 4 equal parts horizontally. Then, divide each of those parts into 2 equal parts vertically. This will create 8 equal parts in total.

Each part represents 3/8 of the whole rectangle. So, 3/4 divided by 2 is equal to 3/8.

How to Multiply and Divide Fractions

Multiplying and dividing fractions are essential skills in mathematics. Fractions represent parts of a whole, and understanding how to manipulate them is crucial for solving various problems.

Multiplying Fractions:

To multiply fractions, simply multiply the numerators (top numbers) and the denominators (bottom numbers) of the fractions. For example, to find 2/3 multiplied by 3/4, calculate 2 x 3 = 6 and 3 x 4 = 12, resulting in the fraction 6/12. However, the fraction 6/12 can be simplified to 1/2.

Dividing Fractions:

Dividing fractions involves a slightly different approach. To divide fractions, flip the second fraction (the divisor) upside down (invert) and multiply it by the first fraction (the dividend). For example, to divide 2/5 by 3/4, invert 3/4 to become 4/3 and multiply it by 2/5: 2/5 x 4/3 = 8/15.

People Also Ask

How do you simplify fractions?

To simplify fractions, find the greatest common factor (GCF) of the numerator and denominator and divide both by the GCF.

What’s the reciprocal of a fraction?

The reciprocal of a fraction is obtained by flipping it upside down.

How do you multiply mixed fractions?

Multiply mixed fractions by converting them to improper fractions (numerator larger than the denominator) and applying the rules of multiplying fractions.

5 Tips for Cross-Multiplying Fractions

5 Tips for Cross-Multiplying Fractions

Cross-multiplying fractions is a quick and easy way to solve many types of fraction problems. It is a valuable skill for students of all ages, and it can be used to solve a variety of problems, from simple fraction addition and subtraction to more complex problems involving ratios and proportions. In this article, we will provide a step-by-step guide to cross-multiplying fractions, along with some tips and tricks to make the process easier.

To cross-multiply fractions, simply multiply the numerator of the first fraction by the denominator of the second fraction, and then multiply the denominator of the first fraction by the numerator of the second fraction. The result is a new fraction that is equivalent to the original two fractions. For example, to cross-multiply the fractions 1/2 and 3/4, we would multiply 1 by 4 and 2 by 3. This gives us the new fraction 4/6, which is equivalent to the original two fractions.

Cross-multiplying fractions can be used to solve a variety of problems. For example, it can be used to find the equivalent fraction of a given fraction, to compare two fractions, or to solve fraction addition and subtraction problems. It can also be used to solve more complex problems involving ratios and proportions. By understanding how to cross-multiply fractions, you can unlock a powerful tool that can help you solve a variety of math problems.

Understanding Cross Multiplication

Cross multiplication is a technique used to solve proportions, which are equations that compare two ratios. It involves multiplying the numerator of one fraction by the denominator of the other fraction, and vice versa. This forms two new fractions that are equal to the original ones but have their numerators and denominators crossed over.

To better understand this process, let’s consider the following proportion:

Fraction 1 Fraction 2
a/b c/d

To cross multiply, we multiply the numerator of the first fraction (a) by the denominator of the second fraction (d), and the numerator of the second fraction (c) by the denominator of the first fraction (b):

“`
a x d = c x b
“`

This gives us two new fractions that are equal to the original ones:

Fraction 3 Fraction 4
a/c b/d

These new fractions can be used to solve the proportion. For example, if we know the values of a, c, and d, we can solve for b by cross multiplying and simplifying:

“`
a x d = c x b
b = (a x d) / c
“`

Setting Up the Equation

To cross multiply fractions, we need to set up the equation in a specific way. The first step is to identify the two fractions that we want to cross multiply. For example, let’s say we want to cross multiply the fractions 2/3 and 3/4.

The next step is to set up the equation in the following format:

1. 2/3 = 3/4

In this equation, the fraction on the left-hand side (LHS) is the fraction we want to multiply, and the fraction on the right-hand side (RHS) is the fraction we want to cross multiply with.

The final step is to cross multiply the numerators and denominators of the two fractions. This means multiplying the numerator of the LHS by the denominator of the RHS, and the denominator of the LHS by the numerator of the RHS. In our example, this would give us the following equation:

2. 2 x 4 = 3 x 3

This equation can now be solved to find the value of the unknown variable.

Multiplying Numerators and Denominators

To cross multiply fractions, you need to multiply the numerator of the first fraction by the denominator of the second fraction, and the denominator of the first fraction by the numerator of the second fraction.

Matrix Form

The cross multiplication can be arranged in matrix form as:
$$a/b × c/d = (a × d) / (b × c)$$

Example 1

Let’s cross multiply the fractions 2/3 and 4/5:

$$2/3 × 4/5 = (2 x 5) / (3 x 4) = 10/12 = 5/6$$

Example 2

Let’s cross multiply the fractions 3/4 and 5/6:

$$3/4 × 5/6 = (3 x 6) / (4 x 5) = 18/20 = 9/10$$

Evaluating the Result

After cross-multiplying the fractions, you need to simplify the result, if possible. This involves reducing the numerator and denominator to their lowest common denominators (LCDs). Here’s how to do it:

  1. Find the LCD of the denominators of the original fractions.
  2. Multiply the numerator and denominator of each fraction by the number that makes their denominator equal to the LCD.
  3. Simplify the resulting fractions by dividing both the numerator and denominator by any common factors.

Example: Evaluating the Result

Consider the following cross-multiplication problem:

  Original Fraction LCD Adjustment Simplified Fraction
 

1/2

x 3/3

3/6

 

3/4

x 2/2

6/8

     

(Reduced: 3/4)

Multiplying the fractions gives: (1/2) x (3/4) = 3/8, which can be simplified to 3/4 by dividing the numerator and denominator by 2. Therefore, the final result is 3/4.

Checking for Equivalence

Once you have multiplied the numerators and denominators of both fractions, you need to check if the resulting fractions are equivalent.

To check for equivalence, simplify both fractions by dividing the numerator and denominator of each fraction by their greatest common factor (GCF). If you end up with the same fraction in both cases, then the original fractions were equivalent.

Steps to Check for Equivalence

  1. Find the GCF of the numerators.
  2. Find the GCF of the denominators.
  3. Divide both the numerator and denominator of each fraction by the GCFs.
  4. Simplify the fractions.
  5. Check if the simplified fractions are the same.

If the simplified fractions are the same, then the original fractions were equivalent. Otherwise, they were not equivalent.

Example

Let’s check if the fractions 2/3 and 4/6 are equivalent.

  1. Find the GCF of the numerators. The GCF of 2 and 4 is 2.
  2. Find the GCF of the denominators. The GCF of 3 and 6 is 3.
  3. Divide both the numerator and denominator of each fraction by the GCFs.
2/3 ÷ 2/3 = 1/1
4/6 ÷ 2/3 = 2/3
  1. Simplify the fractions.
1/1 = 1
2/3 = 2/3
  1. Check if the simplified fractions are the same. The simplified fractions are not the same, so the original fractions were not equivalent.

Using Cross Multiplication to Solve Proportions

Cross multiplication, also known as cross-producting, is a mathematical technique used to solve proportions. A proportion is an equation stating that the ratio of two fractions is equal to another ratio of two fractions.

To solve a proportion using cross multiplication, follow these steps:

1. Multiply the numerator of the first fraction by the denominator of the second fraction.
2. Multiply the denominator of the first fraction by the numerator of the second fraction.
3. Set the products equal to each other.
4. Solve the resulting equation for the unknown variable.

Example

Let’s solve the following proportion:

2/3 = x/12

Using cross multiplication, we can write the following equation:

2 * 12 = 3 * x

Simplifying the equation, we get:

24 = 3x

Dividing both sides of the equation by 3, we solve for x.

x = 8

Simplifying Cross-Multiplied Expressions

Once you have used cross multiplication to create equivalent fractions, you can simplify the resulting expressions by dividing both the numerator and the denominator by a common factor. This will help you write the fractions in their simplest form.

Step 1: Multiply the Numerator and Denominator of Each Fraction

To cross multiply, multiply the numerator of the first fraction by the denominator of the second fraction and vice versa.

Step 2: Write the Product as a New Fraction

The result of cross multiplication is a new fraction with the numerator being the product of the two numerators and the denominator being the product of the two denominators.

Step 3: Divide the Numerator and Denominator by a Common Factor

Identify the greatest common factor (GCF) of the numerator and denominator of the new fraction. Divide both the numerator and denominator by the GCF to simplify the fraction.

Step 4: Repeat Steps 3 If Necessary

Continue dividing both the numerator and denominator by their GCF until the fraction is in its simplest form, where the numerator and denominator have no common factors other than 1.

Example: Simplifying Cross-Multiplied Expressions

Simplify the following cross-multiplied expression:

Original Expression Simplified Expression

(2/3) * (4/5)

(8/15)

Steps:

  1. Multiply the numerator and denominator of each fraction: (2/3) * (4/5) = 8/15.
  2. Identify the GCF of the numerator and denominator: 1.
  3. As there is no common factor to divide, the fraction is already in its simplest form.

Cross Multiplication in Real-World Applications

Cross multiplication is a mathematical operation that is used to solve problems involving fractions. It is a fundamental skill that is used in many different areas of mathematics and science, as well as in everyday life.

Cooking

Cross multiplication is used in cooking to convert between different units of measurement. For example, if you have a recipe that calls for 1 cup of flour and you only have a measuring cup that measures in milliliters, you can use cross multiplication to convert the measurement. 1 cup is equal to 240 milliliters, so you would multiply 1 by 240 and then divide by 8 to get 30. This means that you would need 30 milliliters of flour for the recipe.

Engineering

Cross multiplication is used in engineering to solve problems involving forces and moments. For example, if you have a beam that is supported by two supports and you want to find the force that each support is exerting on the beam, you can use cross multiplication to solve the problem.

Finance

Cross multiplication is used in finance to solve problems involving interest and rates. For example, if you have a loan with an interest rate of 5% and you want to find the amount of interest that you will pay over the life of the loan, you can use cross multiplication to solve the problem.

Physics

Cross multiplication is used in physics to solve problems involving motion and energy. For example, if you have an object that is moving at a certain speed and you want to find the distance that it will travel in a certain amount of time, you can use cross multiplication to solve the problem.

Everyday Life

Cross multiplication is used in everyday life to solve a wide variety of problems. For example, you can use cross multiplication to find the best deal on a sale item, to calculate the area of a room, or to convert between different units of measurement.

Example

Let’s say that you want to find the best deal on a sale item. The item is originally priced at \$100, but it is currently on sale for 20% off. You can use cross multiplication to find the sale price of the item.

Original Price Discount Rate Sale Price
\$100 20% ?

To find the sale price, you would multiply the original price by the discount rate and then subtract the result from the original price.

“`
Sale Price = Original Price – (Original Price x Discount Rate)
“`

“`
Sale Price = \$100 – (\$100 x 0.20)
“`

“`
Sale Price = \$100 – \$20
“`

“`
Sale Price = \$80
“`

Therefore, the sale price of the item is \$80.

Common Pitfalls and Errors

1. Misidentifying the Numerators and Denominators

Pay close attention to which numbers are being multiplied across. The top numbers (numerators) multiply together, and the bottom numbers (denominators) multiply together. Do not switch them.

2. Ignoring the Negative Signs

If either fraction has a negative sign, be sure to incorporate it into the answer. Multiplying a negative number by a positive number results in a negative product. Multiplying two negative numbers results in a positive product.

3. Reducing the Fractions Too Soon

Do not reduce the fractions until after the cross-multiplication is complete. If you reduce the fractions beforehand, you may lose important information needed for the cross-multiplication.

4. Not Multiplying the Denominators

Remember to multiply the denominators of the fractions as well as the numerators. This is a crucial step in the cross-multiplication process.

5. Copying the Same Fraction

When cross-multiplying, do not copy the same fraction to both sides of the equation. This will lead to an incorrect result.

6. Misplacing the Decimal Points

If the answer is a decimal fraction, be careful when placing the decimal point. Make sure to count the total number of decimal places in the original fractions and place the decimal point accordingly.

7. Dividing by Zero

Ensure that the denominator of the answer is not zero. Dividing by zero is undefined and will result in an error.

8. Making Computational Errors

Cross-multiplication involves several multiplication steps. Take your time, double-check your work, and avoid making any computational errors.

9. Misunderstanding the Concept of Equivalent Fractions

Remember that equivalent fractions represent the same value. When multiplying equivalent fractions, the answer will be the same. Understanding this concept can help you avoid pitfalls when cross-multiplying.

Equivalent Fractions Cross-Multiplication
1/2 = 2/4 1 * 4 = 2 * 2
3/5 = 6/10 3 * 10 = 6 * 5
7/8 = 14/16 7 * 16 = 14 * 8

Alternative Methods for Solving Fractional Equations

10. Making Equivalent Ratios

This method involves creating two equal ratios from the given fractional equation. To do this, follow these steps:

  • Multiply both sides of the equation by the denominator of one of the fractions. This creates an equivalent fraction with a numerator equal to the product of the original numerator and the denominator of the fraction used.
  • Repeat step 1 for the other fraction. This creates another equivalent fraction with a numerator equal to the product of the original numerator and the denominator of the other fraction.
  • Set the two equivalent fractions equal to each other. This creates a new equation that eliminates the fractions.
  • Solve the resulting equation for the variable.

Example: Solve for x in the equation 2/3x + 1/4 = 5/6

  • Multiply both sides by the denominator of 1/4 (which is 4): 4 * (2/3x + 1/4) = 4 * 5/6
  • This simplifies to: 8/3x + 4/4 = 20/6
  • Multiply both sides by the denominator of 2/3x (which is 3x): 3x * (8/3x + 4/4) = 3x * 20/6
  • This simplifies to: 8 + 3x = 10x
  • Solve for x: 8 = 7x
  • Therefore, x = 8/7

How to Cross Multiply Fractions

Cross-multiplying fractions is a method for solving equations involving fractions. It involves multiplying the numerator of one fraction by the denominator of the other fraction, and vice versa. This technique allows us to solve equations that cannot be solved by simply multiplying or dividing the fractions.

Steps to Cross Multiply Fractions:

  1. Set up the equation with the fractions on opposite sides of the equal sign.
  2. Cross-multiply the numerators and denominators of the fractions.
  3. Simplify the resulting products.
  4. Solve the resulting equation using standard algebraic methods.

Example:

Solve for \(x\):

\(\frac{x}{3} = \frac{2}{5}\)

Cross-multiplying:

\(5x = 3 \times 2\)

\(5x = 6\)

Solving for \(x\):

\(x = \frac{6}{5}\)

People Also Ask About How to Cross Multiply Fractions

What is cross-multiplication?

Cross-multiplication is a method of solving equations involving fractions by multiplying the numerator of one fraction by the denominator of the other fraction, and vice versa.

When should I use cross-multiplication?

Cross-multiplication should be used when solving equations that involve fractions and cannot be solved by simply multiplying or dividing the fractions.

How do I cross-multiply fractions?

To cross-multiply fractions, follow these steps:

  1. Set up the equation with the fractions on opposite sides of the equal sign.
  2. Cross-multiply the numerators and denominators of the fractions.
  3. Simplify the resulting products.
  4. Solve the resulting equation using standard algebraic methods.