Find the sum of the first n terms of the following arithmetic sequence.
--66, 8, 82, . . .; n = 10
A) -3000
B) 3000
C) 2670
D) -3990

Question

Quizplus · Accepted Answer

The common difference (d) of the sequence is 8 - (-66) = 74. The first term (a) is -66. The sum of the first n terms of an arithmetic sequence is given by S_n = n/2 * [2a + (n-1)d]. Substituting n = 10, a = -66, and d = 74 gives S_10 = 10/2 * [2(-66) + (10-1)74] = 5 * [-132 + 666] = 5 * 534 = 2670.

Find the Sum of the First N Terms of the Following