3x + y = -11
6x - 2y = -2
double the 1st equation and you have
6x + 2y = -22
6x - 2y = -2
Now you can add them to eliminate y, or subtract to eliminate x.
6x - 2y = -2
6x + 2y = -22
6x - 2y = -2
Now you can add them to eliminate y, or subtract to eliminate x.