Posted by Joe on Saturday, September 29, 2012 at 8:39pm.
(x+5y)(7x+3y)How do I solve this. I know I have to somehow combine the x and y but can't remember.

college algebra  Reiny, Saturday, September 29, 2012 at 8:53pm
(x+5y)(7x+3y)
= 7x^2 + 3xy + 35xy + 15y^2
= 7x^2 + 38xy + 15y^2