x=1: Learn to solve equations

version 3.1

Mathematical regards, lot's of improvements coming your way! * Zero - a term from the other side of the equation is now calculated immediately * The expansion of the selection is now a tad faster. Keep me updated if this feels good * The "multiply with -1" button is finally here. Equation played until -x=-1 are no longer cumbersome so solve! Please tell me any problem you see, so I can fix it as soon as possible: https://twitter.com/xgleich1