If f(x) = (5x-2)/4, what is f^-1(y) (the inverse)?

Answer 1

If f(x) = (5x - 2)/4, the inverse g(x) is the function satisfying
f(g(x)) = x, so we have f(g(x)) = (5g(x) -2)/4 = x, or 5g(x) - 2 = 4x, so g(x) = (4x + 2)/5.

You can check that this is the correct answer by computing
g(f(x)), which should = x.