How to solve quadratic equations

We do not have to graph our quadratic equations in order to solve them, instead we could use factoring and then apply the zero product property.

If ab=0 then either a=0 or b=0 or both.


Example

Solve the following equation by factoring:

$$x^{2}-4x=0$$

$$x(x-4)=0$$

Either x is equal to zero or x-4 is equal to zero or both.

The answer to our equation must then be either x=0 or x=4. If we plug x=0 or x=4 into our original equation we will see that we are correct.


Video lesson

Solve the following equation by factoring

$$x^{2}+x=2$$