Please help im being timed

Inverse of f(x)=15x+4

(x) =

Step-by-step explanation:

let y = f(x), then rearrange making x the subject

y = x + 4 ( subtract 4 from both sides )

y - 4 = x ( multiply both sides by 5 to clear the fraction )

5y - 20 = x

Change y back into terms of x with x = (x) , then

(x) = 5x - 20