algebraic equation for constant number that is a percentage or fraction of variable number and steps to solve
equation for variable of which constant is percentage thereof
Arbitrarily, let's assign a value of 1/2 or 0.5 (however you want to notate 50%) for your percentage/fraction.
Isolate the variable to one side. V=2C
Plug in whatever values you know (you should know the constant and the fraction). Solve the equation.
I hope this is what you meant.