Find the partial sum of the arithmetic sequence with the given first term and common difference
-$\mathrm{s}_{6}, \mathrm{a} 1=-12, \mathrm{~d}=-2$
A) -12
B) -72
C) -24
D) -102

Question

Quizplus · Accepted Answer

The formula for the sum of the first n terms of an arithmetic sequence is $ S_n = \frac{n}{2} (2a_1 + (n-1)d) $. For this sequence, $ n = 6 $, $ a_1 = -12 $, and $ d = -2 $. Plugging in these values gives $ S_6 = \frac{6}{2} (2(-12) + (6-1)(-2)) = 3(-24 - 10) = 3(-34) = -102 $.

Find the Partial Sum of the Arithmetic Sequence with the Given