Question

10x+15y=20
-9x-15y=-21

Answer 1

You can solve this system of equations in many ways.

This easiest way, in my opinion, is by addition.

10x+15y=20
+
-9x-15y=-21
---------------------
x=-1

Now you have x = -1

plug that into any of the equations to get y


You can also solve this with substitution as well.