What are the solution of the following system X-y=-4 / 4x-4y=-16

Solve equation [1] for the variable  y  

 [1]    y = -x - 4

Plug this in for variable  y  in equation [2]

  [2]    4x - 4•(-x -4) = 16

  [2]    8x = 0

Solve equation [2] for the variable  x  

   [2]    8x = 0  

  [2]    x = 0  

By now we know this much :  

   x = 0

   y = -x-4

Use the  x  value to solve for  y  

   y = -(-0/32766)-4 = -4  

Solution :

{x,y} = {0/32766,-4}

{x,y} = {0,-4}

the answer to your question is b.