you just plug in what Y equals into the second equation:
-2x-3(6x-11) = -7
then you solve the equation:
-2x-18x+33 = -7
-20x+33 = -7
subtract 33 from each side:
-20x = -40
divide each side by -20
x = 2
then you plug x into the original equation:
y = 6(2)-11
y = 12-11
y = 1
so x = 2 and y = 1