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]