Question

the sum of the first three terms of a geometric sequence is 91 and it's common ratio is 3. determine the first term of the sequence​

Answer 1

a=7

Explanation:

1st term=a

2nd term=ar

3rd term=ar^2

a+are+ar^2=91

r=3

a+3a+(3)^2a=91

a+3a+9a=91

13a=91

a=91/13

a=7