Question

How do you factor `kx + px - ky - py`?

Answer 1

`(k+p)(x-y)`

Explanation:

Group `kx+px-ky-py`
as
`color(white)("XXX")(kx+px) - (ky+py)`

Extract the common factor `x` from the first term
and the common factor `y` from the second term
`color(white)("XXX")(k+p)x - (k+p)y`

Extract `(k+p)` as a common factor of both of these terms
`color(white)("XXX")(k+p)(x-y)`