I'm having a hard time with algebra right now, is anyone able to explain this for me?? Classify the function as exponential growth or decay: y = 1/3 × 5^x

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