The one you put as (-13, -6) is incorrect, it is (-13, 6)
-2 * -3 = 6 -Two negatives gives a positive
The one you put as (-15,-4) is incorrect, it is (-15, 4)
-36 / -9 = 4 -Once again two negatives gives a positive.
The one you put as (-15,-3) is incorrect, it is (-15, 3)
-3 + 6 = 3
The one you put as ( -14, 2) is incorrect, it is (-14, 0)
-1 - (-1) = 0
Hope this helps you! It took a while for me to do it. Happy thanksgiving, here's a turkey!