How do I solve a quadratic equation by completing the square?

The first step is to make sure that the coefficient of x^2 is 1 by dividing all terms by a (where a equals the coefficient of x^2). Then we must write the quadratic equation as a square plus another term. To do this, half the x coefficient to get b, and write out (x + b)^2 minus b^2. Move all constants (terms that do not involve x) to the other side of the equals sign and then square root both sides. Finally, isolate x to solve the equation.