If the difference of a number and nine is tripled the result is five more than a number

[15 points, algebra 2]simplify the complex fraction and find the restrictions.

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?

Table which ratio is equivalent to 3: 7? 6: 7 3: 21 24: 56 15: 30