Find the sum of the sequence.
-$$\sum _ { k = 1 } ^ { 4 } ( - 1 ) ^ { k } \cdot - 8 k$$
A) $- 16$
B) $- 80$
C) 80
D) 4,096

Question

Quizplus · Accepted Answer

The given sequence is a sum of terms of the form $(-1)^k \cdot -8k$ from $k=1$ to $k=4$. Calculating each term: - For $k=1$, the term is $(-1)^1 \cdot -8(1) = 8$. - For $k=2$, the term is $(-1)^2 \cdot -8(2) = -16$. - For $k=3$, the term is $(-1)^3 \cdot -8(3) = 24$. - For $k=4$, the term is $(-1)^4 \cdot -8(4) = -32$. Adding these terms together: $8 - 16 + 24 - 32 = -16$.

Find the Sum of the Sequence ∑k=14(−1)k⋅−8k\sum _ { k = 1 } ^ { 4 } ( - 1 ) ^ { k } \cdot - 8 kk=1∑4​(−1)k⋅−8k

Find the Sum of the Sequence $\sum _ { k = 1 } ^ { 4 } ( - 1 ) ^ { k } \cdot - 8 k$