Question 24114
Did you solve for x and get x= -3?  If so, then substitute x =-3 back into one of the equations, either one will do, let's use the first one.  This is just BIG TIME SUBSTITUTION!!  As they say in that Glade commercial, "PLUG IT IN, PLUG IT IN!!"


2x-3y = 9
2(-3) - 3y = 9
-6 - 3y = 9


Add +6 to each side:
-6+6 -3y = 9+6
-3y = 15
y= -5


Check in the other equation:

-5x - 3y = 30
-5(-3)-3(-5)= 30
15+15= 30
It checks!!


R^2 at SCC