What is the sum of the first seven terms of the geometric series that begins with −4 and has a common ratio of 5?(1 point)
Using the formula for the sum of the first n terms of a geometric series, we have:
S = a(1 - r^n)/(1 - r)
Given that a = -4, r = 5, and n = 7, we can plug these values into the formula:
S = -4(1 - 5^7)/(1 - 5)
S = -4(1 - 78125)/(-4)
S = -4(-78124)/(-4)
S = 312496
Therefore, the sum of the first seven terms of the geometric series is 312496.