What is the cube root of 512m^12n^15

Val and tony get paid per project. val is paid a project fee of $44 plus $12 per hour. tony is paid a project fee of $35 plus $15 per hour. write an expression to represent how much a company will pay to hire both to work the same number of hours on a project.

With number 11 ( show how you got the answer)

Assume that y varies inversely with x. if y=1.6 when x=0.5 find x when y=3.2