jika fog(x)=6x+8/4x-1:x1/4 dan g(x)=2x+3, maka nilai daei f invers1 (1)

(fog) (x) = 6x + 8 / 4x-1
f(2x-3)=6x + 8 / 4x-1
misal
t= 2x-3
2x = t+3
x = t+3 / 2
f(x) = 6( t+3 / 2) + 8 / 4( t+3 / 2) - 1
=2t + 3 + 8 / 2t+6-1
=2t+11 / 2t+5
maka
f(x) = 2x+11 / 2x+5
inverskan
y = 2x+11 / 2x+5
y(2x+5)= 2x+11
2xy+5y= 2x+11
2xy-2x=-5y+11
x(2y-2)=-5y+11
x=-5y+11 / 2y-2
f-¹(x) = -5x+11 / 2x-2

maka hasilnya f-¹(x) = -5x+11 / 2x-2