One model for the ideal body weight, w, for men (in kilograms) is W=50 + 2.3 (h-60) rewrite the function in order to express height as a function of weight

This is a quite simple algebraic problem. The trick is to manipulate the terms through transposing. Always remember that if you want to transfer a term to the other side, take its opposite sign. The solution is as follows:

W=50 + 2.3 (h-60)

2.3 (h - 60) = W - 50

h - 60 = (W - 50) / 2.3

h = (W - 50) / 2.3 + 60