63
positive
They're all positive.
136 - -129 = 265
129 minus -128.6 is 257.6
129 + 34 = 163
1467+129 = 1596
129 times 10 to the negative 6 (129 x 10-6) in standard notation = 0.000129
-129 + 22 = -107
115 + 14 = 129
129
129
130
How about: 100+29 = 129