If your interested in solving algebraic equations then google around. There are many many websites that teach things like how to solve these equations and even go over the rules you have to follow with them.
What we're interested in right now though, is if its beneficial to have solved that EV equation that i made since we can always use a math solver if we get stuck on the algebra. S=16.93150... is right but we're really only interested in maybe two decimal places maximum.