First, let's group the numbers in pairs:(1-2) + (3-4) + (5-6) + ... + (997-998) + (999-1000)
Now, let's simplify each pair:-1 + -1 + -1 + ... + -1 + -1
Since there are 500 pairs, the sum of all these pairs would be:-500
So, 1-2 + 3-4 + 5-6 + ... + 997-998 +999-1000 = -500.
First, let's group the numbers in pairs:
(1-2) + (3-4) + (5-6) + ... + (997-998) + (999-1000)
Now, let's simplify each pair:
-1 + -1 + -1 + ... + -1 + -1
Since there are 500 pairs, the sum of all these pairs would be:
-500
So, 1-2 + 3-4 + 5-6 + ... + 997-998 +999-1000 = -500.