how to solve
1/100-2/100+3/100-4/100+....+99/100-1??
and this??
-1/100+2/100-3/100+4/100-....-99/100+1??
You have
1-2 + 3-4 + ... + 99-100
= (-1) + (-1) + (-1) ... + (-1) (50 times)
= -50
Naturally, the 2nd sum is then +50
1/100-2/100+3/100-4/100+....+99/100-1??
and this??
-1/100+2/100-3/100+4/100-....-99/100+1??
1-2 + 3-4 + ... + 99-100
= (-1) + (-1) + (-1) ... + (-1) (50 times)
= -50
Naturally, the 2nd sum is then +50