Why do you factor a quadratic equation before you solve?

Answer 1

Factoring can sometimes give you easy answers to quadratics. Look at the following example: x2 + x - 2 = 0 Now let's factor it: (x - 1)(x + 2) = 0 Now, think back to elementary multiplication. Zero times anything is equal to zero. If we keep this in mind, we know that when we have a quadratic like the equation above, we only need to get one of the sections to equal zero. Once we find a value of x which results in one part being zero, it will multiple through and make the entire side equal to zero. So let's look back at each part of our example. (x - 1) To get this to equal zero, we need to set x = 1 (x + 2) To get this to equal zero, we need to set x = -2 So now we have our answer: x can be either 1 or -2 to solve the equation. Nice and simple, because we started out by factoring the equation.