Answer:
216
Step-by-step explanation:
A=2(wl+hl+hw)=2·(12·2+6·2+6·12)=216
a) (f+g)(x) = f(x) + g(x) = -4x + 5x = x
b) -9(x) = -9x? I have no idea what this means.
c) (f o g)(x) = (f(g(x)) = f(5x) = -4 (5x) = -20x
