Factor by Grouping 7a-7b+an-bn

$7 a - 7 b + a n - b n$

Factor out the greatest common factor from each group.

Group the first two terms and the last two terms.

$(7 a - 7 b) + a n - b n$

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

$7 (a - b) + n (a - b)$

Factor the polynomial by factoring out the greatest common factor, $a - b$ .

$(a - b) (7 + n)$