# How do you write a polynomial of least degree with roots 5 and -9?

Jan 30, 2017

$\left(x - 5\right) \left(x + 9\right) = 0$

#### Explanation:

And so I expand the given expression out:

${x}^{2} + 9 x - 5 x - 45 = 0$

${x}^{2} + 4 x - 45 = 0$

And clearly this has roots at $x = 5 , x = - 9$