Answer:
x=3 and y=-6.
Explanation:
Given the system of linear equations:
[tex]\begin{gathered} x+y=-3 \\ 3x+y=3 \end{gathered}[/tex]To solve the system using the substitution method, we follow the steps below:
Step 1: Make x the subject in the first equation
[tex]\begin{gathered} x+y=-3 \\ x=-3-y \end{gathered}[/tex]Step 2: Substitute x=-3-y into the second equation
[tex]\begin{gathered} 3x+y=3 \\ 3(-3-y)+y=3 \end{gathered}[/tex]Step 3: Solve the equation for y.
[tex]\begin{gathered} -9-3y+y=3 \\ -2y=3+9 \\ -2y=12 \\ y=\frac{12}{-2} \\ y=-6 \end{gathered}[/tex]Step 4: Solve for x using any of the equations.
[tex]\begin{gathered} x=-3-y \\ =-3-(-6) \\ =-3+6 \\ x=3 \end{gathered}[/tex]The solutions to the system of equations are x=3 and y=-6.