Respuesta :

MrsTuthill
Injective- (one-to-One)
so
Replace the f(x) with y 
10-4x
Interchange the variables
x=10-4y
Solv for y.
y= 5/2 - x/4
So solve for y and replace with f-1 (x).
and it equals 
f-1 (x)=5/2- x/4