Factor by Grouping 7z^2+21z-az-3a

$7 z^{2} + 21 z - a z - 3 a$

Step 1

Factor out the greatest common factor from each group.

Group the first two terms and the last two terms.

$(7 z^{2} + 21 z) - a z - 3 a$

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

$7 z (z + 3) - a (z + 3)$

Step 2

Factor the polynomial by factoring out the greatest common factor, $z + 3$ .

$(z + 3) (7 z - a)$