Question

g(a)=a-2
f(a)=2a+2
find g(a)•f(a)

Answer 1

Answer:

$(a - 2)(2a + 2) \\ = {2a }^{2} + 2a - 4a - 4 \\ = {2a}^{2} - 2a - 4 \\ ({2a}^{2} - 4a) + (2a - 4) \\ 2a(a - 2) + 2(a - 2) \\( a - 2)(2a + 2) \\ a = 2 \\ a = - 1$

Answer 2

Answer:

$g(a).f(a) = (a - 2)(2a + 2) \\ = 2 {a}^{2} + 2a - 4a - 4 \\ = \boxed{2 {a}^{2} - 2a - 4}$

(2a²-2a-4) is the right answer.