How to Solve Quadratic Equations Using Factoring
A quadratic equation contains a degree two polynomial and
Hi, my name is Bassem Saad. I'm a Math Ph.D. candidate at U.C. Davis, and I'm here today for About.com to show you how to solve a quadratic equation.Remember, a quadratic equation contains a degree two polynomial and a single variable. For our first example, we'll use the factoring method. In this quadratic equation we want to get all our non-zero variables to one side, so we just add three x to both sides. Then we'll get x squared, plus three x, plus two, equals zero.Notice that the constant term, two, is divisible by one and two only. Also notice that our coefficient of the degree one term, three, equals one plus two. So we know that we can factor our polynomial into x plus one and x plus two. So we want to find the x value so that this equation is true. Now, that means we need either this term to be equal to zero, or find the x that makes this term to be equal to zero.So, notice if we put in x equals minus one, this term is zero. And whatever this term is when we plug in x equals to minus one doesn't matter, because zero times anything equals zero. We do the same thing on this side. If we plug in x equals minus two, we'll get zero over here. And again, zero times anything equals zero. Now we know our two solutions to the quadratic equation. Thanks for watching, and to learn more, visit us on the web at About.com.