Solving by substitution method.
If we clear y in equation 1, we get:
[tex]y=3+x[/tex]
Now, if we substitute this result into equation 2, we have
[tex]3x+(3+x)=-1[/tex]
By clearing parenthesis, we get 3x+3+x=-1.
Now, by combining similar terms, we obtain
[tex]4x+3=-1[/tex]
If we move +3 to the right hand side as -3, we have
[tex]\begin{gathered} 4x=-1-3 \\ 4x=-4 \\ x=-\frac{4}{4} \\ x=-1 \end{gathered}[/tex]
Finally, by substituting this result into out first equation, we get
[tex]\begin{gathered} y=3+(-1) \\ y=3-1 \\ y=2 \end{gathered}[/tex]
Therefore, the solution of the system is x=-1 and y=2.
