To know the answer, is convenient to replace some values of "n" in the sum .
The result would appear after adding up every value of the expression when n=1,2,3.....,150.
When n=1, the expression takes the value of (-1): .
When n=2, the expression takes the value of (-2): .
Following this way, for every n, we will obtain -n, then, the sum will be: . This sum can actually be expressed as , which is the result of solving the initial expression of the sum .
Finally, the sum of n=-1 to n=-150 equals -11,325.
=18 sides
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. This sum can actually be expressed as
, which is the result of solving the initial expression of the sum
.