when you have a - sign before parenthesis, its -1. sooo...
-1(1 + 7x) -6(-7 - x) = 36
Now distribute.
-1 × 1 = -1
-1 × 7x = -7x
-6 × -7 = 42
-6 × -x = 6x
-1 - 7x + 42 + 6x = 36
Combine Like Terms
-1 + 42 = 41
7x + 6x = 13x
13x + 41 = 36
- 41 - 41
13x = - 5
x = -5/13
