Nomor 17 Beserta jalannya

f(x) = 2x - 3
g(x) = 1/(3x + 1)

(fog)(x)
= 2/(3x + 1) - 3
= (2 - 3(3x + 1))/(3x + 1)
= (2 - 9x - 3)/(3x + 1)
= (-9x - 1)/(3x + 1)

Ingat :
Misal :
h(x) = (ax + b)/(cx + d)
h^-1 (x) = (-dx + b)/(cx - b)

••
Maka
(fog)^-1 (x) = (-x - 1)/(3x + 9)
atau
(fog)^-1 (x) = - (x + 1)/(3x + 9)