What is the simplified form of this expression?
(-x2 + x) + (4x2 − x − 1)

Explanation:
The x^2 terms add to -x^2+4x^2 = 3x^2
The x terms add to x+(-x) = x-x = 0x = 0
The constant -1 doesn't have anything to pair with it, so it just stays as is.
So overall we end up with 3x^2-1