3 - B
4 - A
5 - A
6. x = y + 6
2x + y = 0
2(y+6) + y = 0
2y + 12 + y = 0
3y = -12
y = -4
x = 6 - 4 = 2
Solution would be: (2, -4) [ Option B ]
7) 3x + y = -8
2x - y = 3
Add both equations,
5x = -5
x = -1
Now, 2(-1) - y = 3
-y = 3 + 2
y = -5
Solution would be: (-1, -5) [ Option A ]
Hope this helps!