Answer: The required sum of the given geometric series is - 32766.
Step-by-step explanation: We are given to find the sum of a 7-term geometric series if the first term is -6, the last term is -24,576 and the common ratio is 4.
We know that,
if 'a' is the first term and 'r' is the common ratio of a geometric series, then its sum up to n terms is given by

In the given geometric series,
first term, a = -6 and common ratio, r = 4.
Since r = 4 > 1, so the sum up to 7 terms is

Thus, the required sum of the given geometric series is - 32766.