Question

1-2+3-4+5-6...+2007-2008=?

Answer 1

1-2+3-4+5-6...+2007-2008 = (1-2)+(3-4)+(5-6)...+(2007-2008)=-1 + (-1) + (-1) + ... + (-1) = 1004 * (-1) = - 1004

смотрит колько  -1

1-2 одна  2/2 = 1

1-2 + 3 - 4 две  4/2 = 2

1-2 + 3 - 4 + 5 - 6 три  6/2 = 3

1-2+3-4+5-6...+2007-2008 ////  2008/2 = 1004

нашли закономерность старшее число делим на 2  

Answer 2

To find the sum of the given arithmetic series, you can group the terms in pairs and then calculate the sum of each pair. The general form of each pair can be written as (n - (n+1)), where n is an odd number. The sum of each pair is -1, as the two terms cancel each other out. Since there are 1004 pairs in total (2008 terms divided by 2), the sum of the entire series will be:

Sum = (Number of pairs) x (Sum of each pair) Sum = 1004 x (-1) = -1004

So, the sum of the series 1-2+3-4+5-6...+2007-2008 is -1004.