Question 256543
-7x-2y= -13
x-2y=11 --> x = 2y+11 
-------------
Sub for x into the 1st eqn
-7(2y+11) - 2y = -13
-14y-77 - 2y = -13
-16y = 64
y = -4
---------
sub for y into either eqn
x-2y=11
x-2(-4) = 11
x+8 = 11
x = 3