Question

How do you combine `(-16x^2 + 13x - 13) - (-19x^2 - 11x + 12)`?

Answer 1

Because of the `-`sign you reverse all the signs in the second term (and of course you change the `-` into a `+`:

`=(-16x^2+13x-13)+(19x^2+11x-12)`

Now get rid of the brackets and add like terms:
`=-16x^2+13x-13+19x^2+11x-12`
`=(-16x^2+19x^2)+(13x+11x)+(-13-12)`

`=3x^2+24x-25`