Question 271088
Hello, 
Here we go. 
9X-3Z=20
3X+6Z=2 
Multiply the first equation by 2 to get:
18X-6Z=40 Now, add this to the second:
3X+6Z=2 
And we get:
21X=42 Divide each side by 21 to get:
X=2 Plug 2 into the first equation to get:
18-3Z=20 Subtract 18 from both sides and divide by -3 to get:
Z=-2/3
You'll see that plugging these answers into the equations works out right. 
So don't be so hard on yourself. You are RIGHT!
RJ
Check out a book I wrote at:
www.math-unlock.com