50
(-1) + 2 + (-3) + 4 + ... + (-99) + 100 =
= 2 - 1 + 4 - 3 + .. + 100 - 99
= 1 + 1 + .. + 1
= 50×1
= 50
Answer:
50.
Step-by-step explanation:
Each pair of numbers add up to 1:
-1 + 2 = 1, -3 + 4 = 1 and so on
There are 50 of theses pairs so the value is 50.
