g(x)= -1/2x+2 g^-1(x)=.....

-1/(2x + 2) = y
-1/y = 2x+2
-1/y = 2(x+1)
-1/2y = x+1
-1/2y - 1 = x
.jadi

g^-1(x) = -1/2y - 1

Maaf kalo salah, semoga membantu:)