Please edit the question and attach a picture of the figure so that we can answer more accurately :)
Answer:
16
Step-by-step explanation:
x=7-9
The general form of the geometric sequence is

, where a sub n is the number term you're looking for (we're looking for the tenth term). a sub 1 is the first term in the sequence (ours is -6), r is the common ratio, and n-1 is the numbered term you're looking for minus 1. Our formula then looks like this:

. Simplify it to

. Take 2 to the 9th power then multiply it by -6 to get -3072. C is your answer.
So you want to cross multiply. then it would be 3x=25 then divide by 3 isolating x. x=25/3