-8-(-18) = -8+18 = 10
8-12 = -4
-8-(-12) = -8+12 = 4
-8-2 = -10
-7-6 = -13
7-6 = 1
-7-(-6) = -7+6 = -1
7-(-6) = 7+6 = 13
-8-(-18) = -8+18 = 10
8-12 = -4
-8-(-12) = -8+12 = 4
-8-2 = -10
-7-6 = -13
7-6 = 1
-7-(-6) = -7+6 = -1
7-(-6) = 7+6 = 13