Easy Multi-Function Calculator

The Easy Multi-function Calculator application was designed to make your calculation easy. It can do arithmetic, function, and equation, even the two unknowns single equation. It also supports complex numbers if the formula has no complex number but only real (e.g. If your type -4 to evolution, itll give you the answer: 2i).
Another example, if there are two unknowns in a single equation: x+2x+8, the delta is -4, less than 0, the calculator will give you the answer: one is (-2+2i)/2, another is (-2-2i)/2 instead of "Error".
Another feature is we tell you why its an error, for example if you type a formula, itll tell you "Error: Out of range" instead of single word "Error".