Answer:
x=-10 and y=10.
Explanation:
Given the system of equations:
[tex]\begin{gathered} -y=x \\ 3x+5y=20 \end{gathered}[/tex]Substitute x with -y in the second equation.
[tex]\begin{gathered} 3x+5y=20 \\ 3(-y)+5y=20 \end{gathered}[/tex]Next, solve for y.
[tex]\begin{gathered} -3y+5y=20 \\ 2y=20 \\ y=\frac{20}{2} \\ y=10 \end{gathered}[/tex]Use y to solve for x.
[tex]\begin{gathered} x=-y \\ x=-10 \end{gathered}[/tex]Thus, the solution to the system of equations is x=-10 and y=10.
