Find the first term (a) of ago sequince in which the common ratio is 2 and sum of the first 10 terms are 93

Answer 1

I will assume this is an arithmetic sequence.
Let's just use our formulas
we know d = 2
sum(10) = 93 ---> n = 10, a = ?
(10/2)(2a + 9(2)) = 93
5(2a + 18) = 93
10a + 90 = 93
10a = 3
a = .3

check:
10th term = a+9d = .3 + 18 = 18.3
sum(10) = (10/2)(first + last) = 5(.3+18.3) = 93

Answer 2

a common ratio indicates a g.p. (or, as nasra calls it, a go)

S10 = a(r^10-1)/(r-1)
a(2^10-1) = 93
a = 93/1023

and that's "the sum ... is 93"