Answer:
Explanation:
First you need to make sure that the numbers you are working with are the same type of unit. 1 mile is equal to 5,280 feet.
Next you have to do 21,129 divided by 5,280 which is 4.00189394.
Third, you can round that to 4
Finally, 4 miles/hour × 2 hours = 8 miles (rounded to four decimal places).
Hope this helped!