Question

The arithmetic sequence a_ia i ​ a, start subscript, i, end subscript is defined by the formula: a_1 = -53a 1 ​ =−53a, start subscript, 1, end subscript, equals, minus, 53 a_i = a_{i - 1} + 6a i ​ =a i−1 ​ +6a, start subscript, i, end subscript, equals, a, start subscript, i, minus, 1, end subscript, plus, 6 Find the sum of the first 880880880 terms in the sequence.

Answer 1

Answer:

S880= 2,273,920

Step-by-step explanation:

For an arithmetic sequence, a1 =  -53 and

when n = 2,

The first 3 terms forms an arithmetic sequence as shown;

-53, -47, -41...

Sum of nth term of an arithmetic sequence is expressed as;

a is the first term = -53

n is the number of term = 880 (since we want to find the sum of the first 880 terms)

d is the common difference = 6

S880 = 880/2 {2(-53)+ (880-1)6}

S880 = 440{-106+(879)6}

s880= 440{-106+5274}

S880 = 440 * 5168

S880= 2,273,920