Tentukan nilai dari f(4) jika g(x)=3x-5 dan (gof)=(2x-3)²

(gof)=(2x-3)² = 4x²-12x +9
g(x)=3x-5
(gof)(x) = g(f(x))
4x²-12x+9 = 3(f(x) -5
4x²-12x+9+5 = 3(f(x))
4x²-12x+14= 3(f(x))
f(x) = 4x²-12x+14/ 3
f(x) = 2x²-6x+7/3
f(4)= 2.4²-6.4+7
f(4) = 32-24+7
f(4) = 15/3
f(4)= 5