Question

Find the sum of 3+ 4 -- -- 5 7

Answer 1

Answer:

First term a=3

Last term = 57

Common difference =1

Sn=n/2(2a+n-1)d

First we need to find n

An= a+n-1 into d

57=3+n-1into 1

54= n-1

55=n

Sum of term = 55/2 (2into3+55-1 into 1)

=27.5 (60)

=1650

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