Question

How do you check that you factored a quadratic correctly?

Answer 1

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 :)