jika f(x)=1/2x-1 dan g(x)=2x+4,maka (g°f) infers (10)=…

dianggaap f(x) = 1/(2x -1)..........???
gof(x) = g(f(x)) = g(1/(2x - 1)
= (2/(2x - 1)) + 4
=(2 + 4(2x - 1))/(2x - 1)
gof(x) = y = (8x - 2)/(2x - 1)
y(2x - 1) = 8x - 2
2xy - y = 8x - 2
2xy - 8x = y - 2
x(2y - 8) = y - 2
x = (y - 2)/(2y - 8)
gof^-1(x) = (x - 2)/(2x - 8)
gof^-1(10) = (10 - 2)/(2*10 - 8) = 2/3