Answer: B
Step-by-step explanation: I saw that it went -2 and then 4.5 was added on and thus verifying that B is the correct answer.
Just to help you, that formula is saying that 1 mile is equivalent to 5280 feet, i.e. the number of feet is equal to 5280 * number of miles.
So, you know the number of feet = 21,120 and have to convert that into the equivalent number of miles:
f = 5280m => m = f / 5280
m = 21,120 / 5280 = 4 miles
Answer: 4 miles
