Question

I was supposed to simplify - (-a - 1) - (a - 1), I got 2a + 2, It would be great if could tell me what I may have done wrong. I need a really deep explanation on this because I have already asked two tutors and am still confused on way the answer is +2.

Answer 1

Given:

- (-a - 1) - (a - 1)

First, distribute the minus sign

a + 1 - a + 1

Combine like terms

a - a +1 + 1

2

Answer : 2