3 + 2x - y = 0 and - 3 - 7y = 10x
-3 -3 and - 10x + 3 -10x + 3
------------------- and ------------------------------
2x - y = - 3 and - 10x - 7y = 3
2x - y = - 3 /* 5
-10x - 7y = 3
--------------------------
10x - 5y = - 15
-10x - 7y = 3
--------------------
- 12 y = -12
--------- -------------
-12 -12
------------------------
y = 1
3 + 2x - 1 = 0
2 + 2x = 0
--------- ----------
-2 -2
------------------------
2x = - 2
--- -----
2 2
-----------------------
x = - 1