Help please #3 i need to turn it in

What is the inverse of the function f(x)=4x+8

Determine the fraction of total interest owed. after the fourth month of a 12-month loan: the numerator is: {(n + ) + (n + ) + (n + ) + (n + )} = , and the denominator is: {(n) + (n + 1) + + (n + )} = . therefore, the fraction is numerator/denominator (to the nearest tenth) =

If f(x) = x+8 and g(x) = 4x- 3, find (f+g)(x)