How do you check that you factored a quadratic correctly?

1 Answer
Mar 15, 2018

If both the roots satisfy the quadratic equation, then you have factorised it correctly.

Explanation:

I will try explaining with an example.
x^2+4x-12=0
The roots are 2 and -6.
Now simply put the values in the quadratic equation.

First, I will try -6
(-6)^2+4(-6)-12=0
36-24-12=0
cancel36-cancel36=0
0=0
which is true.

Now, I will try 2
2^2+4*2-12=0
4+8-12=0
cancel12-cancel12=0
0=0
which is also true.

:. Our answer was correct.

Hope you got it :)