Fungsi invers,tolong bntu kk

f(x) = 3 / (x + 1)
y = 3 / (x + 1)
y(x + 1) = 3
yx + y = 3
yx = 3 - y
x = (3-y) / y

jadi 
f⁻¹(x) = (3-x) / x