y = +/- (x + 3), for x => 0
y = +/- (3 - x), for x < 0
So, it looks like two "V" shaped absolute value graphs ('arms' with grapients of 1 or -1), symmetric about the y-axis, one pointed up with 'vertex' at (0, 3), the other pointed down with vertex at (0, -3).
How did I get this? I took cases: Case 1, x=> 0, then |x| = x, so |y| = x + 3, so y = x + 3 or -(x + 3).
Case 2, x < 0, |x| = -x, ...
Now, try |y| + |x| = 3...