Answer:
Line 3
Step-by-step explanation:
The problem's lines are:
Line 1. 5(x - 5) = 15
Line 2. 5x - 25 = 15
Line 3. 5x - 25 = 15 - 25
Line 4. 5x = -10
Line 5. 5x/5 = -10/5
Line 6. x = -2
The first error is in Line 3, where 25 was subtracted from just the right side, and where 25 should have been added to both sides instead.
