This calculator solves equations fo one variable. The equation may contain many variables.
What does it mean to solve an equation?
It means transforming the equation into a form where one of the variables stands alone. The advantage of this is that you may insert the values of the other variables if you know them, then you just have to do a simple calculation.
At school, it is especially important in physics to solve equations. Of course you can solve those physical equations with Mathepower.