If y varies directly with x, find the constant of variation if x = 7 when y = 14, then find y when x = 45 If y varies jointly with x and z, and y = 18, x = 3, when z = 2, then find y when x = 5 and z = 3 15 If y varies inversely with x, and x = 9 when y = 45, then find y when x = 27 12/7
