Question

What is the sum of a 6-term geometric sequined if the first term is 22 and the last term is 1299078

Answer 1

Answer:

1461460

Step-by-step explanation:

From the question given, we obtained the following data:

a = 22

Last term = T6 = 1299078

Let us find the common ratio(r)

Tn = ar^(n-1)

T6 = ar^5

1299078 = 22r^5

Divide both side by 22

r^5 = 1299078/22

r^5 = 59049

Take the fifth root of both side

r = 5√ 59049

r = 9

Now we can find the sum of the 6th term as follows

Sn = a[(r^n) — 1] / (r —1)

S6 = 22[(9^6) — 1] / 9—1

S6 = 22[(9^6) — 1] / 9—1

S6 = 22[531441 — 1] / 8

S6 = 22[531440] /8

S6 = 22 x 66430

S6 = 1461460