Factor ax+ay-bx-by

$a x + a y - b x - b y$

Factor out the greatest common factor from each group.

Group the first two terms and the last two terms.

$(a x + a y) - b x - b y$

Factor out the greatest common factor (GCF) from each group.

$a (x + y) - b (x + y)$

Factor the polynomial by factoring out the greatest common factor, $x + y$ .

$(x + y) (a - b)$