Use the formula to evaluate the series 2-10+50-250+...-a6

Answer 1

Hi Naya,

the formula used to evaluate the (finite) series is

Sn = a1 (1 - r^n) / (1 - r)

with the given geometric series,

a1 = 2

r = -5

n = 6

Please let me know if you need further help.

Katherine