A: (f + g)(x) = f(x) + g(x)
(f + g)(x) = 5x - 12 + 11x + 2
(f + g)(x) = 16x - 10
B: (f • g)(x) = f(x) • g(x)
(f • g)(x) = (5x - 12)(11x + 12)
(f • g)(x) = 55x² + 60x - 121x - 144
(f • g)(x) = 55x² - 61x - 144
C: Plug g(x) into f(x) as x.
f[g(x)] = 5(11x + 12) - 12
f[g(x)] = 55x + 60 - 12
f[g(x)] = 55x + 48