2x - 2y < 6
2x - 2x - 2y < 6 - 2x
-2y < 6 - 2x
-2 -2
y < -3 + x
2x - 2(-3 + x) < 6
2x + 6 - 2x < 6
2x - 2x + 6 < 6
0x + 6 < 6
-6 -6
0x < 0
0 0
x < 0
2(0) - 2y < 6
0 - 2y < 6
+0 +0
-2y < 6
-2 -2
y < -3
(x, y) < (0 -3)
x - y < 9
x - x - y < 9
-y < 9
y < -9
x + 9 < 9
-9 -9
x < 0
0 - y < 9
+0 +0
y < 9
(x, y) < (0, 9)