Question

How do you simplify `(-9x^2 - 4x - 4) - (-9x^2 - 11x + 12)`?

Answer 1

`=color(blue)(7x -16`

Explanation:

`(-9x^2 - 4x - 4) - (-9x^2 - 11x + 12)`

`=-9x^2 - 4x - 4 +9x^2 + 11x - 12`

Grouping like terms:
`=color(red)((-9x^2 +9x^2)) +color(blue)((-4x + 11x)) -4 - 12`
`=0 +color(blue)(7x) -16`
`=color(blue)(7x -16`