f(x)= 2x+3 dan g(x)= 9-x maka (F°g)(x)

(fog)(x) =
f(x) = 2(9-x) + 3
= 18 - 2x + 3
= -2x + 21

semoga membantu
maaf jika salah

(Fog) (x) = f. (g(x))
= f(9-x)
= 2(9-x) + 3
= 18 - 2x + 3
= -2x + 21