Word problems and polynomial inequalities?

Question

You drive 90m along a hwy and then take a 5 mile run. Your driving rate is 9 times that of your running rate. (there is a graph with points aprox.(1.7, 8) (3,5) (5,3) (7,2) (11,1.5)

The function supplied is:
f(x)= 90/9x + 5/x = 15/x

the question askes
Descrive your running rate if you have no more than a total of 5hrs of running and driving. Use a rational inequality to solve the problem.

If I could get a setup I believe I could solve this.

Answer 1

x is the running speed. Total time elapsed is indeed f(x) = 15/x (do you understand why?).

You're told that f(x) = 15/x <= 5

What does that tell you about x?

(Hint: The answer is that it tells you that you're running at at least 3 miles per hour.)

(Personally, I can't run 5 20-minute miles in succession and even so I wouldn't drive 90 miles down a highway at 27 miles per hour just to take a run, but I digress ...)

Answer 2

what you will desire to do is, if n(t) is in hundreds, then you definately ought to locate the time, because it says, while that selection reaches 10,000. Then, n(t) = a hundred at t = unknown, which yields a hundred = -t^4 + 5t^3 + 5t^2 +6t, and now you will come across the aspects. wish this helps