7. In which step does a mistake first occur? 8 + 2 + (3 X 3 -2)
Step 1: 8 +2 + (3 x 1)
Step 2: 8 +2 + 3
Step 3: 4 + 3
Step 4: 7

8 . In which step does a mistake first occur?
(24+3 + 10)-14 + 2
Step 1: (8 + 10) -14 + 2
Step 2: 18 -14+2
Step 3: 4 +2
Step 4: 2

PEMDAS is an acronym for the order of operations. Parentheses, exponents, multiplication, division, addition, subtraction.

For question 7:
8 + 2 + (3 x 3 -2)
I believe the mistake is in step 1. I believe it should be:
8 + 2 + (9 -2)

We go by order of operations from left to right.

For question 8, the mistake is in step 1. They divided 24 by 3 instead of adding. It should be:
(27 + 10) - 14 + 2