Question

Please help me figure this one out !!!

Answer 1

These are "composite" functions.
g(x+a)  means insert (x+a) into g(x) to replace every x:
g(x+a) - g(x) = -5(x+a)^2 +4(x+a) +5x^2 - 4x
 = -5(x^2 + 2ax + a^2) +4x +4a + 5x^2 - 4x
Now just Multiply and sum up the answer.