Question

f(x)=(x+2)^2 and g(x)=x^2-(x+2)^2. Find f(x)-g(x)

Answer 1

Have you considered constructing it?

f(x) - g(x) = [(x+2)^2] - [x^2-(x+2)^2]

Simplify.

Answer 2

look at the equations, using [(x+2)^2] - [x^2-(x+2)^2], add and subtract like terms