Linear and Quadratic Equation Solver

This solver takes one equation in one variable and finds the value that makes it true, provided the equation reduces to a straight line or a quadratic. Type something like 3x + 5 = 2x - 7 or x^2 - 5x + 6 = 0 and it expands the brackets, moves everything to one side, prints the standard form and solves it, then puts the answer back into the original equation and shows both sides so you can see that it checks out. Brackets, a squared term and division by a plain number are understood, while a variable in a denominator, a radical, a trigonometric function or a second letter are refused with a message instead of being guessed at. It is a solver rather than a general algebra system, so it does not factor, graph or handle higher powers.