Question

Find the missing term(s) of the geometric sequence: 39, a2 , 975, ... Hint: r can be positive or negative.

Answer 1

9514 1404 393

Answer:

±195

Explanation:

For some common ratio r, your missing term satisfies ...

39r = a2

a2·r = 975

So, ...

975 = 39r^2

25 = r^2

r = ±√25 = ±5

The missing term a2 = 39r could be either of 195 or -195.