How do you check that you factored a quadratic correctly?

1 Answer
Jade
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 :)

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