y = -2x - 4
y = 2x + 4
substitute the first equation into the second equation to find x;
-2x - 4 = 2x + 4
-4 = 2x + 4 + 2x
-4 = 4x + 4
-4 - 4 = 4x
-8 = 4x
-2 = x
solve for y given the value of x into the first equation;
y = -2x - 4
y = -2(-2) - 4
y = 0
the answer is;
x = -2, y = 0 or (-2, 0)
hope this helps, God bless!