Respuesta :

bcalle
(-2x -1) - (x - 7)
distribute the negative through the second set of parenthesis
-2x - 1 - x + 7
- 3x + 6
olorundaral
first you distribute the negative in front of -(x-7)

then you get 
-2x-1-x+7
then you can simplify easily
to get
-2x-x-1+7

= -3x+6