The posted speed limit is 45 miles per hour. Select all of the rates that are faster than 45 miles per hour.

A. 45 km per hour
B. 64.1 km per hour
C. 86.4 km per hour
D. 91 km per hour

choose all that apply

Sanya noticed that the temperature was falling at a steady rate of 1.4 degrees every hour from the time that she first checked her outdoor thermometer. by 6 a.m., the temperature had fallen 21 degrees. which expression can you use to find how many hours earlier she had first checked the thermometer?