Question

How do you factor completely `ax-2x+ay-2y`?

Answer 1

I got: `(x+y)(a-2)`

Explanation:

Collect `a` from the first and third and `-2` from the second and fourth:
`a(x+y)-2(x+y)=`

now collect `(x+y)`:

`=(x+y)(a-2)`