4+1+(-2)+...+(-371)=

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4+1+(-2)+...+(-371)= what?

Guest Apr 28, 2015

+128474

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Best Answer

The sum, S_n, is given by :

(n/2)[(2a + (n-1)d ] where a is the first term = 4, n = 126 = the number of terms, and d = -3, the common difference

So we have

(126/2) [ 2(4) + (125)(-3)] =

-23121

CPhill Apr 28, 2015

CPhill · Answer 1 · 2015-04-28T06:12:09

The sum, S_n, is given by :

(n/2)[(2a + (n-1)d ] where a is the first term = 4, n = 126 = the number of terms, and d = -3, the common difference

So we have

(126/2) [ 2(4) + (125)(-3)] =

-23121