Solve for one variable in one of the equations:
5x + y = -13
y = -13 - 5x
plug that in for the variable in the other equation:
6x + 6y = -6
6x + 6 (-13 - 5x) = -6
Solve for the variable:
6x - 78 - 30x = -6
-24x - 78 = -6
-24x = 72
x = -3
Plug that in for the variable in any of the original equations:
5x + y = -13
5 (-3) + y = -13
Solve for the variable:
-15 + y = -13
y = 2
(-3, 2)