Consider the guven system of equations,
[tex]\begin{gathered} x-y=-1 \\ 2x+y=4 \end{gathered}[/tex]It is asked to find the correct graph which represent the solution of this system.
Logic: Find the solution and see which graph gives the same solution.
Add the equations,
[tex]\begin{gathered} (x-y)+(2x+y)=-1+4 \\ 3x+3 \\ x=1 \end{gathered}[/tex]Substitute this value in the first equation,
[tex]\begin{gathered} 1-y=-1 \\ y=1+1 \\ y=2 \end{gathered}[/tex]Thus, the given system has a unique solution (1,2).
Now, observe that only the graph given in option (c) shows the line intersecting at point (1,2).
Therefore, option (c) is the correct choice.
