How do I evaluate a Sum(Σ) and a Pi(π)

Question 1:

4
Σ (-2)^k
k = 0


Question 2:

0
π (k^2 - 1)
k = -3

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Please help me, thank you!

upper case sigma, Σ, represents a sum. substitute integers from lower index to upper index and add results

4
Σ (-2)^k = (-2)^0 + (-2)^1 + (-2)^2 + (-2)^3 + (-2)^4
k = 0

= 1 - 2 + 4 - 8 + 16 = 11


upper case Pi, π, represents a product. substitute integers from lower index to upper index and multiply results

0
π (k^2 - 1) = [(-3)² - 1]∙[(-2)² - 1]∙[(-1)² - 1]∙[(0)² - 1]
k = -3

= 8∙3∙0∙(-1) = 0



hope that helps