Jika f(x) =x2 +3x – 4 dan g(x) = x – 4, maka (fo g) (x)

Fog(x) = f(g(x))
fog(x) = (x – 4)² + 3(x – 4) – 4
fog(x) = x² – 8x + 16 + 3x – 12 – 4
fog(x) =  x² – 8x + 3x + 16 – 12 – 4
fog(x) = x² – 5x