Tentukan nilai dari f(8) jika g(x)=x+2 dan (fog) (x) = (x-2)(3x+1)

g(x) = x + 2

f(g(x)) = f(8)
g(x) = 8
x + 2 = 8 ---> x = 6

f(g(x)) = (x - 2)(3x + 1)
f(8) = f(g(6))
f(g(6)) = (6 - 2)(3.6 + 1)
f(8) = 4 . 19
f(8) = 76 ✔