Let f(x) be the decreasing function defined by f(x) = 2x³ - 3x² + 4x - 5, where x > 0. If g(x) is the inverse function of f(x), which of the following is a correct expression for g(x)?
1) g(x) = (f(x) + 5) / 2
2) g(x) = (f(x) - 5) / 2
3) g(x) = (f(x) + 5) / 3
4) g(x) = (f(x) - 5) / 3