The Quadratic Formula is a well known formuala used to solve quadratic equations; a quadratic equation is an equation (=) that has a squareroot symbole. To solve these you can use a number of things, but my favourite way is the Quadratic Formula.
To start you must know the Quadratic Formula which is x= -b +or-
After you have plugged in the numbers the rest is pretty sympol, you just solve after that.