Question 124554
6x^2+5xy-21y^2
6*-21=-126 multiply the 1st and last coeficients.
-9, 14 factors of =126 whose sum is 5.
6x^2-9xy+14xy-21y^2
3x(2x-3y)+7y(2x-3y) Factoring by grouping.
(3x+7y)(2x-3y)
.
Ed