Answer:
3
Step-by-step explanation:
Given the function f(x) = (5x+1)/2
We are to find the inverse first as shown;
let y = f(x)
y = (5x+1)/2
Replace y with x
x = (5y+1)/2
Make y the subject of the formula;
2x = 5y+1
5y = 2x-1
y = (2x-1)/5
f^-1(x) = (2x-1)/5
f^-1(8) = 2(8)-1/5
f^-1(8) = 16-1/5
f^-1(8) = 15/5
f^-1(8) = 3
Hence the answer is 3
