Respuesta :

Answer:  [tex](-9,-3)[/tex]

Step-by-step explanation:

Given the following system of equations:

[tex]\left \{ {{2x=-78-20y} \atop {-x=-51-20y}} \right.[/tex]

In order to solve the System of equations, you can use the Substitution method. The steps are:

1. You can solve for "x" from the second equation:

[tex]-x=-51-20y\\\\x=51+20y[/tex]

2. Substitute the equation obtained into the first original equation:

[tex]2x=-78-20y\\\\2(51+20y)=-78-20y[/tex]

3. Now you must solve for "y":

[tex]102+40y=-78-20y\\\\40y+20y=-78-102\\\\60y=-180\\\\y=\frac{-180}{60}\\\\y=-3[/tex]

4. Substitute the value of "y" into the equation [tex]x=51+20y[/tex] and evaluate:

[tex]x=51+20(-3)\\\\x=51-60\\\\x=-9[/tex]

Then, the solution is:

[tex](-9,-3)[/tex]