about a day late, but... it already isolated one of the variables for you, so you can just take the first equation and substitute it into the second:
2x - 3(5x - 6) = 4
2x - 15x + 18 = 4
-13x + 18 = 4
-13x = -14
x = 14/13
based on that alone, you can see that B is your answer, but you can still plug it in to make sure:
5(14/13) - 6 = y
(70/13) - 6 = y
y = -8/13
your answer is B