If f(x)=5x+2f(x) = 5x + 2f(x)=5x+2, what is the inverse function f−1(x)f^{-1}(x)f−1(x)?
f^{-1}(x) = \frac{x-2}{5}
f^{-1}(x) = \frac{x+2}{5}
f^{-1}(x) = 5x - 2
f^{-1}(x) = \frac{1}{5x+2}