Question

-7x-2y=-13 and x-2y=11 Substitution method

Answer 1

Multiply one of them by -1 so one of the -2y is positive
-1(-7x-2y=-13)=7x+2y=13
Then add the two equations
  7x+2y=13
+  x-2y=11
========
8x=24 - the 2y and -2y cancel out. Now solve for x
x=3 Now plug the x back into one of the equations

3-2y=11 Now solve for y
-2y=11-3
-2y=8
y=-4

So x=3 and y=-4

Hope this helps!

Answer 2

X - 2y = 11
x = 11 + 2y

Now, substitute the value of x in first equation, 
-7x - 2y = -13
-7(11 + 2y) - 2y = -13
-77 - 14y - 2y = -13
-16y = -13 + 77
y = -64/16
y = -4

Now, substitute the value of y in 2nd equation, 
x - 2y = 11
x - 2(-4) = 11
x + 8 = 11
x = 11 - 8
x = 3

In short, Your Answer would be: (3, -4)

Hope this helps!