Diket f(x)=2x-4&g(x)=2x+5

tentukan:
1.(GinversOFinvers)(x)
2.(FinversOGinvers)(4)
3.(GinversOFinvers)(18)
4.(fog)invers(x)
5.(fog) invers (10)
plus cara
THX

Diket f(x)=2x-4&g(x)=2x+5

$begin{aligned} text{perhatikan bahwa}\ f(x)&=2x-4\ y&=2x-4\ y+4&=2x\ frac{y+4}{2}&=x\ frac{y+4}{2}&=f^{-1}(y)\ therefore f^{-1}(x)&=frac{x+4}{2}\ text{selanjutnya}\ g(x)&=2x+5\ y&=2x+5\ y-5&=2x\ frac{y-5}{2}&=x\ frac{y-5}{2}&=g^{-1}(y)\ therefore g^{-1}(x)&=frac{x-5}{2}\ text{Soal no. 1}\ (g^{-1}circ f^{-1})(x)&=g^{-1}(f^{-1}(x))\ &=g^{-1}left(frac{x+4}{2}right)\ &=frac{frac{x+4}{2}-5}{2}cdotfrac{2}{2}\ &=frac{x+4-10}{4}\ &=frac{x-6}{4}\ text{Soal no. 3}\ (g^{-1}circ f^{-1})(18)&=frac{18-6}{4}\ &=frac{12}{4}\ &=3\ text{Soal no. 4}\ (fcirc g)^{-1}(x)&=(g^{-1}circ f^{-1})(x)\ &=frac{x-6}{4}\ text{soal no. 10}\ (fcirc g)^{-1}(10)&=frac{10-6}{4}\ &=frac{4}{4}\ &=1\ end{aligned}$