Find the sum of the first 6 terms of 3 - 6 + 12 + …

Answer:
[tex] S_6 = -63 [/tex]
Step-by-step explanation:
The sequence above is a geometric sequence.
The common ratio (r) = [tex] \frac{-6}{3} = \frac{12}{-6} = -2 [/tex]
The common ratio < 1, therefore, the formula for the sum of nth terms of the sequence would be: [tex] S_n = \frac{a_1(1 - r^n)}{1 - r} [/tex]
a1 = 3
r = -2
n = 6
Plug in the values into the formula
[tex] S_6 = \frac{3(1 - (-2^6)}{1 - (-2)} [/tex]
[tex] S_6 = \frac{3(1 - (64)}{1 + 2} [/tex]
[tex] S_6 = \frac{3(-63)}{3} [/tex]
[tex] S_6 = -63 [/tex]