Question

The 5th term in a geometric sequence is 160. The 7th term is 40. What are the possible values of the 6th term of the sequence? (1 point)
±70
70
±80
80

Answer 1

Geometric sequence has the property that any 3 consecutive terms are in Geometric progression.

so you can directly use the formula that
\(\Large a_6^2 = a_5\times a_7\)
just plug in and find 2 possible values of 6th term, ie., a6

Answer 2

Perhaps it would be a wee bit clearer to write the notation as
\[a_6 = \sqrt{(a_5 \times a_7)}\]