F(x)=5x-4 dan g(x)=x2+6. tentukan a.(fog) (x) b.(gof)(x) c.(fog)(5)

A. (fog)(x) = fungsi f dengan komposisi g

f (g (x)) = 5 (g (x)) – 4 = 5 (x^2+6)-4 = 5x^2 + 30 -4

b. (gof)(x)

g (f (x)) = (f (x))^2 + 6 = (5x-4)^2 + 6 =
25x^2 – 40x + 22

c. (fog)(5) = 5. (5)^2 + 30 – 4 = 125 +26 = 151