Dik f(x) = 1 - 5x/ x+2, x tdk sama dngn 3. Maka nilai f-^1(4) = ..

f(x)=y= 1 - 5x/(x+2)
(x+2)y=1-5x
xy+2y=1-5x
xy+5x=1-2y
x(y+5)=1-2y
f^-1(x)=(1-2x)/(x+5)
f^-1(4)=(1-2(4))/(4+5)=-7/9