# How do I factor x^2-10xy-11y^2?

$\left(x - 11 y\right) \left(x + y\right)$

#### Explanation:

We have

${x}^{2} - 10 x y - 11 {y}^{2}$

And we're looking to set up factors.

Looking at the expression, we know we need $x$ terms so that they will multiply and make a ${x}^{2}$. We also need $y$ terms, one being an $11 y$ and the other being $y$ and one of them being negative.

So we have, in part:

$\left(x \pm Y\right) \left(x \pm Y\right)$, where $Y$ is our $y$ terms, and we also have:

$\left(X \pm 11 y\right) \left(X \pm y\right)$, where $X$ is our $x$ terms

We can now see that we also need an $- 10 x y$ term, and we can get that by having $- 11 y , y$ terms. Putting it altogether:

$\left(x - 11 y\right) \left(x + y\right)$