Answer:
(D) 86
Step-by-step explanation:
According to the question, the equation will be= \sum_{n=1}^{7}2(-2)^{n-1}.
Now,substituting the values of n from 1 to 7 in the above equation, we have
\sum_{n=1}^{7}2(-2)^{n-1} = \(2(-2)^{0} + 2(-2)^{1}+ 2(-2)^{2}+ 2(-2)^{3} + 2(-2)^{4}+ 2(-2)^{5}+ 2(-2)^{6}\)
=\(2-4+8-16+32-64+128\)
=\(170-84\)
=\(86\)
Hence, the correct answer will be equal to 86.
