What does this formula mean?

What is the measure of x, in degrees

What is the 9th term in the geometric sequence described by this explicit formula? an=-6. (2)(n-1) apex

When a 757 passenger jet begins its descent to the ronald reagan national airport in washington, d. c., it is 3900 feet from the ground. its angle of descent is 6 degrees. how far must the plane fly to reach the run way? a. 37,106 ft b. 37,310.4 ft c. 23,456.6 ft d 2,492.7 ft