ips yg soal matematika kelas 2 SMA

f(x) = x^2 - 4
g(x) = 2x - 6
(f o g)(x) = -4
f(g(x)) = (2x - 6)^2 - 4 = -4
4x^2 - 24x + 36 - 4 + 4 = 0
x^2 - 6x + 9 = 0
(x - 3)(x - 3) = 0
x = 3

C