The statement basically says the equation, so all that is needed is interpretation. First, look at the "three times". If the height is just three times the radius, it will look like 3r = h, because if any number is put into r, then h will be three times larger. Then it says "5 units less", which can be put as r - 5 = h with the same logic as the previous explanation. Combining those two gives us, lo and behold, 3r - 5 = h.
