2 + 2 = ? plz help me

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?

Walking at a constant rate of 8 kilometers per hour, juan can cross a bridge in 6 minutes. what is the length of the bridge in meters?

20 ! brainliest ! add and simplify your answer.