x-2y=8; 6x+6y=42
Try to get a variable all by itself.
x-2y=8
Subtract x on both sides.
-2y= 8-x
Subtract 8 on both sides.
-2y-8= -x
Divide by -1, so that x is not negative.
-2/-1= 2 -8/-1=8
2y+8=x
Now plug that in.
8(2y+8)+6y=42
16y+64+6y=42
22y+64=42
22y=-22
y=-1
Now, plug that in.
x-2(-1)=8
x+2=8
x=6
(6,-1)
Check.
6-2(-1)=8
6+2=8
8=8
8(6)+6(-1)=42
48-6=42
42=42
The solution is (6,-1)
I hope this helps!
~kaikers