Factoring by Grouping Factoring by Grouping. Factor each completely. 1) 5mn + 25m + 3n. 3 + 15n. 2. 2) 4au + 24av − 5bu − 30bv. 3) 15xw + 18xk + 25yw + 30yk. 4) 7xy + 28x.2 pages