If a car is traveling at the constant rate of 67x=y, how far will it have traveld in 8.4 hours?

Which statement most accurately describe why the division property of exponents does not apply to the expression (-8)^2/(-3)^4

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?

In a column proof the right column states your reasons