# If you divide a polynomial by a binomial, how do you know if the binomial is a factor of the polynomial?

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Expert Answers

jeew-m | Certified Educator

The polynomial with two terms is called a binomial.

For example `x^3+2x+2` is a polynomial and `x+2` is a binomial.

We can use the remainder theorem to find out whether a binomial is a factor of a polynomial.

In remainder therem it states that a polynomial f(x) is divided by (x-a) which is a binomial the remainder is given by f(a).

So when it comes to a factor f(a) = 0

Now the problem is clear.

*You can substitute the value of binomial (which binomial equate to 0) to the polynomial and check whether the remainder is 0.If so it is a factor otherwise not.*

Just see the example for more.....

polynomial `f(x) = x^2+2x+1`

Binomial `= (x+1)`

`(x+1) = 0` when `x = -1`

`f(-1) = (-1)^2+2(-1)+1 = 0`

So `(x+1)` is a factor of `x^2+2x+1.`