Published on 3 Dec 2012Learn how to solve quadratic equations by completing the square. When solving a quadratic equation by completing the square, we first take the constant term to the other side of the equation and create a perfect square trinomial with the quadratic term and the linear term. If the coefficient of the quadratic term is not 1, we factor out the coefficient before creating the perfect square trinomial.The perfect square trinomial is created by adding to both side of the equation, the square of half the coefficient of the linear term (the term whose variable is not squared). Note that you must account for the factored out value when adding the square of half the linear term to the other side of the equation. Then the perfect square trinomial is evaluated and then we solve for the variable to get the solution(s) to the quadratic equation. . Whether you're working symbolically (as in the last example) or numerically (which is the norm), the key to solving by completing the square is "practice, practice, practice". By so doing, the process will become more "automatic", and you'll be much more likely to remember the steps when you're taking the next test.. for the purposes of this answer ill use the equation X^2+4X-8=0 1.) move the "C" to the other side of the equation - X^2+4X=8 2.) If the coefficient before the first X is not one you have to factor it out but in this case it is one so you can move to step 3..