Unit 5 Lesson 25
Objective: Using Multiplicative Inverses to Solve Equations.
In this section, you will learn how to solve equations by using multiplicative inverses.
To solve an equation, you must isolate the variable. You want to get the variable by
itself. In order to isolate the variable, the coefficient of the variable must equal 1.
If the coefficient, the number in front, of the variable is a fraction, then you will multiply both
sides of the equation by the inverse of the coefficient.
Example 1 Solving a one-step equation.
Solution
When you multiply
by the multiplicative
inverse, the
coefficient of y
becomes 1. 1 • y = y.
Original equation.
Multiply both sides by multiplicative inverse.
Multiply.
Example 2 Solving a two-step equation.
Solution
Original equation.
Add 20 to each side.
Simplify
Multiply both sides by multiplicative inverse.
Multiply.
Example 2 Solving a two-step equation.
Solution
Original equation.
Subtract from each side.
Simplify
Multiply both sides by multiplicative inverse.
Multiply.