if (3-x), (6),(7-x) is a geometric sequence calculate (a)the two possible values of x (b) common ratio (c) sum of the sequence

Answer 1

since there is a common ratio,
6/(3-x) = (7-x)/6
so, solve for x
use that to find the ratio.
Then you can find the 1st term and use the GP sum formula.

I must say, not the ratio I expected...