Question

Anne solved 5(2x) - 3 = 20x + 15 for x by first distributing 5 on the left side of the equation. She got the answer x = -3. When she substituted-3 into the original equation her answer was incorrect. Explain Anne's error, and find the correct answer.

Answer 1

-9/5

Explanation:

she should do the multiplying 5 and 2x first then do the calculation

10x - 3 = 20x +15

-3 - 15 = 20x - 10 x

-18 = 10x

x = -18/10➡ x = -9/5