Math help don't understand it

Question

For the function f(x)=−3x^2+2x+2, evaluate and fully simplify each of the following.

f(x+h)−f(x)/h

Answer 1

f(x) = -3x^2 +2x+2

f(x+h)= -3(x+h)^2 + 2(x+h) +2

= -3(x^2+2xh+h^2) + 2x+2h+2

= -3x^2 -6xh+ 3h^2 +2x +2h +2

f(x+h)- f(x) = -6xh+3h^2 +2h

(f(x+h)-f(x))/h = -6x+3h+2