Question 22478
Substute -4 in place of x and -12 in place of y and see if you
get a true result on both equations.

-4-(-12)=8
      8=8

2(-4)+(-12)= 2o
-8-12 =20
   -20=20

The point gives a true result in the first equation but not in the second one.
The point (-4,-12) is not a solution for this system of equations.

Cheers,
Stan H.