21ab-14ax+15by-10xy

Group the first two terms and the last two terms.

(21ab-14ax)+15by-10xy

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

7a(3b-2x)+5y(3b-2x)

7a(3b-2x)+5y(3b-2x)

Factor the polynomial by factoring out the greatest common factor, 3b-2x.

(3b-2x)(7a+5y)

Factor by Grouping 21ab-14ax+15by-10xy