Answer:
x = -8
Step-by-step explanation:
Step 1: Write equation
5x - 7(x + 1) = 9
Step 2: Solve for x
Step 3: Check
Plug in x to verify it's a solution.
5(-8) - 7(-8 + 1) = 9
-40 - 7(-7) = 9
-40 + 49 = 9
9 = 9