1. The problem statement, all variables and given/known data The main sequence lifetime of a star, T, is related to it's luminosity, L, in an equation of the form T[itex]\propto[/itex]L^-0.7 Use this equation to derive the form of the mass-luminosity relation for main sequence stars. I know that I'm aiming for around L[itex]\propto[/itex]M^3.5 Don't have a clue where to start, I know it'll be simple but I'm stuck. Any help is greatly appreciated. Thanks, Matt.