Donald Q. answered • 03/13/15
Tutor
New to Wyzant
Guess And Check Discovery
= 10a(2y-x) + 21b(2y-x)
= (10a + 21b) (2y - x)
When using FOIL to check it, you note that 10a is multiplied by 2y and by - x, and
you note that 21b is multiplied by 2y and by -x.
