Dik f(x)= 2x + 4 dan (gof)(x) = 4x² + 12x +6 maka tent rumus g(x)=...?

f(x)  = 2x + 4
(gof)(x) = 4x^2 + 12x + 6

=> (g)(f(x)) = 4(2x + 4)^2 + 12(2x+4) + 6
=>            = 4(4x^2 + 16x + 16) + 24x + 48 + 6
=>            = 16x^2 + 64x + 64 + 24x + 48 + 6
=> g(fx)    = 16x^2 + 88x + 118