Download Lesson 4 - Solving Multiplication Equations

Lesson 9-4
Example 1 Solve a Multiplication Equation
Solve 6x = 18. Check your solution.
 Model the equation.
 Divide the 18 counters equally into 6 groups.
There are 3 in each group.
Check
6x = 18
Write the original equation.
?
6(3)  18
18 = 18
Replace x with 3.
This sentence is true. 
The solution is 3.
Example 2 Solve a Multiplication Equation
Solve −4x = 24.
−4x = 24
4 x 24

4 4
1x = −6
x = −6
Write the equation.
Divide each side by −4.
−4 ÷ (−4) = 1, 24 ÷ (−4) = −6
1x = x
The solution is −6.
Check this solution.
Example 3 Use an Equation to Solve a Problem
GEOMETRY The area of a rectangle is 5.4 square meters, and its width is
0.6 meter. Write an equation to find the length of the rectangle.
Let
= the length of the rectangle.
The area of a rectangle
5.4
5.4 = 0.6
5.4 0.6

0.6 0.6
9=
is equal to its length times its width.
=
0.6
Write the equation.
Divide each side by 0.6.
Simplify.
The length of the rectangle is 9 meters.
Check 5.4 = 0.6(9) is true. 