Solve Equations with Fractions

In this lesson, you will learn to solve equations containing fractions. The goal when you are solving equations with fractions is no different than when working with other types of numbers – isolate the variable on one side of the equation.

Example 1

Solve equations by adding or subtracting:

day 84.1

day 84.2

Example 2

Solve equations by multiplying or dividing:

Fraction equations often call upon the Multiplicative Inverse Property

Multiplicative Inverse Property
Words Numbers Algebra
The product of a nonzero number and its reciprocal is one. day 84.3 day 84.4

day 84.5

day 84.6

Investigate

Erin needs day 84.8 cup of detergent for her laundry.  She has day 84.7 cup of detergent in the bottle. Write and solve an equation to find out how much detergent she will have left in the box.

Strategy  

Summarize the problem, using only key words or phrases.

Erin has day 84.7 cup of detergent and needs day 84.8 cup. How much will remain?

Next, translate the words into math. Use a variable to represent the remaining amount of detergent.

Total Detergent is the amount needed for laundry       and             the amount left

day 84.7 = day 84.8 + d

Solution

day 84.9

 

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