Just by looking at this question, I say there is no solution because these two equations do not touch or meet on the xy-plane.
- х= -у.........A
6x - бу = 12.........B
Solve A for x.
-x = - y
Divide both sides by negative 1.
Doing so, we get x = y. Plug this into B.
6x - 6y = 12
6(y) - 6y = 12
The left side becomes zero.
0 = 12 is a false statement.
Answer: There is no solution to this system of
equations in two variables.
Understand?