Evaluate the Sum $$\sum _ { \mathrm { k } = 1 } ^ { 4 } ( - 1 ) ^ { \mathrm { k } \cdot 9 \mathrm { k } }$$

question 33

Multiple Choice

Evaluate the sum. Round to two decimal places, if necessary.
- $$\sum _ { \mathrm { k } = 1 } ^ { 4 } ( - 1 ) ^ { \mathrm { k } \cdot 9 \mathrm { k } }$$

• A) 6561
• B) 90
• C) 18
• D) \(- 90\)