None portinoal of nonprotinolal

The formula for the volume of a rectangular prism is v = lwh. a rectangular prism has a length of 2y 3 and width of 5y. the volume of the prism is 20y 10 + 70y 4 . what is the height of the prism? show your work.

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?

Can someone me with #s 8, 9, and 11. with just one of the three also works. prove using only trig identities.