Solve (f+g)(-4) when f(x)=x+2 and g(x)=x^2-x
f(x) = x + 2g(x) = x^2 - x(f + g)(x) = x + 2 + x^2 - x = x^2 + 2(f + g)(-4) = (-4)^2 + 2 = 16 + 2 = 18
