Question

Which of the following methods will solve the equation (5x – 7)3 = 42

a) Divide the left side of the equation by 3, add 7 to the right side of the
equation, and multiply both sides by 3.
b) Divide both sides by 3, add 7 to both sides, and multiply both sides by 3.
c) Add 7 to both sides, divide both sides by 3, and multiply the left sides by 3.
d) Multiply both sides by 3, add 7 to both sides, and then divide both sides by 3.

Answer 1

Divide both sides by 3, Add 7 to each side ,Divide each side by 5

Explanation:

(5x – 7)3 = 42

Divide both sides by 3

(5x – 7)3/3 = 42/3

5x-7 = 14

Add 7 to each side

5x-7+7 = 14+7

5x = 21

Divide each side by 5

5x/5 = 21/5

x = 21/5