Question 302120
2y-3x=4 
2y-5x=8
Solving by elimination.
Subtract the 2nd equation from the 1st to get:
2x = -4
x = -2
---
Substitute into either of the original equations and solve for "y":
2y -3(-2) = 4
2y + 6 = 4
2y = -2
y = -1
---
Solution: (-2,-1)
=================================================================
y= -3x+7, 
y= -2x- 5
---
Solve by substitution:
-3x+7 = -2x-5
Add 3x to both sides to get:
x-5 = 7
Add 5 to both sides to get:
x = 12
---
Substitute into either of the original equations and solve for "y":
y = -3(12) + 7
y = -36 + 7
y = -29
---
Solution: (12,-29)
====================================================
 
x+y = 8
x-y = 12
---
Solve by elimination:
Add the two equations to get:
2x = 20
x = 10
---
Substitute and solve for "y":
10+y = 8
y = -2
---
Solution: (10,-2)
=========================
Cheers,
Stan H.