ginnie12w3
Feb 15, 2011, 08:25 PM
How do you answer this 
 
-7x-8y=9
-4x+9y=-22
 
Elimination please
Unknown008
Feb 16, 2011, 07:18 AM
Method 1:
 
1. Multiply the first equation by 4 and the second equation by 7. 
2. Subtract one equation from the other.
3. Solve for the resulting variable.
4. Use that known variable to get the last variable.
 
Method 2:
 
1. Multiply the first equation by 9 and the second equation by 8. 
2. Add both equations together.
3. Solve for the resulting variable.
4. Use that known variable to get the last variable.