Question

Subtract -7n +2 from 2n - 1

Answer 1

2n - 1    -      -7n + 2     You combine like terms with subtracting
2n - 7n = -5n
-1 - 2 = -3
So -7n + 2     -     2n - 1 = -5n - 3

Answer 2

2n - 1 - (-7n +2)
= 2n - 1 + 7n  - 2
= 9n -3 

hope that helps