# How do you use polynomial division to determine whether x=3 is a root of #x^3+x^2+15-x#?

##### 1 Answer

Divide

If you can divide without a remainder,

If you have a remainder, it's not a root.

#### Explanation:

Well, just to check if

But of course, it is also possible to determine the outcome with polynomial division.

To do so, you must divide

*I know that in some countries, a different notation for long division is being used but I will use the one that I'm familiar with and I hope that it will be no problem for you to rewrite it in your notation if necessary.*

At the end of the computation, there is the remainder

As you have a remainder, it means that