What is the inverse of the function f(x) = 2x + 1?

What is the slope of a line that is perpendicular to y = 3x + 1

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?

Iknow its nothing to do with education, but what type of thing should i wrote here? ? : ) its for mcdonald's btw.