Question

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

Answer 1

`(x-11y)(x+y)`

Explanation:

We have

`x^2-10xy-11y^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 `11y` and the other being `y` and one of them being negative.

So we have, in part:

`(xpmY)(xpmY)`, where `Y` is our `y` terms, and we also have:

`(Xpm11y)(Xpmy)`, where `X` is our `x` terms

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

`(x-11y)(x+y)`