Write out the first three terms and the last term of the arithmetic sequence.
-$$\sum _ { i = 1 } ^ { 100 } - 3 i$$
A) $- 3 - 6 - 9 - \ldots - 300$
B) $- 3 + 9 - 27 + \ldots - 900$
C) $- 3 - 9 - 27 - \ldots - 900$
D) $- 1 - 3 - 6 - \ldots - 300$

Question

Quizplus · Accepted Answer

The given sequence is an arithmetic sequence with the first term $a_1 = -3$ and a common difference $d = -3$. The $n$th term of an arithmetic sequence is given by $a_n = a_1 + (n - 1)d$. For $n = 100$, the last term is $a_{100} = -3 + (100 - 1)(-3) = -3 - 297 = -300$. The first three terms are $-3, -6, -9$, and the last term is $-300$, matching option A.

Write Out the First Three Terms and the Last Term ∑i=1100−3i\sum _ { i = 1 } ^ { 100 } - 3 ii=1∑100​−3i

Write Out the First Three Terms and the Last Term $\sum _ { i = 1 } ^ { 100 } - 3 i$