Evaluate the sum. Round to two decimal places, if necessary.
-$$\sum _ { \mathrm { k } = 1 } ^ { 4 } ( - 1 ) ^ { \mathrm { k } } ( \mathrm { k } + 2 )$$
A) 2
B) $- 18$
C) 10
D) 18

Question

Quizplus · Accepted Answer

The sum can be calculated by substituting the values of $k$ from 1 to 4 into the given expression and adding them together. For $k=1$, the term is $(-1)^1(1+2) = -3$. For $k=2$, the term is $(-1)^2(2+2) = 4$. For $k=3$, the term is $(-1)^3(3+2) = -5$. For $k=4$, the term is $(-1)^4(4+2) = 6$. Adding these together, $-3 + 4 - 5 + 6 = 2$.

Evaluate the Sum ∑k=14(−1)k(k+2)\sum _ { \mathrm { k } = 1 } ^ { 4 } ( - 1 ) ^ { \mathrm { k } } ( \mathrm { k } + 2 )k=1∑4​(−1)k(k+2)

Evaluate the Sum $\sum _ { \mathrm { k } = 1 } ^ { 4 } ( - 1 ) ^ { \mathrm { k } } ( \mathrm { k } + 2 )$