Question

12 + 5x - 9(2x - 1)

Explanation:

Step1: Expand the parentheses

$12 + 5x - 9(2x - 1) = 12 + 5x - 18x + 9$

Step2: Combine like x terms

$12 + (5x - 18x) + 9 = 12 - 13x + 9$

Step3: Combine constant terms

$12 + 9 - 13x = 21 - 13x$

Answer:

$21 - 13x$