We have to identify the rational function among the given functions.
Rational function is a function that is the ratio of two polynomials. It is rational because one polynomial is divided by the other polynomial, like a ratio.
1. Consider the first function 
, since it is not a function that is the ratio of two polynomials. So, it is not a rational function.
2. Consider the second function 
, since it is not a function that is the ratio of two polynomials. So, it is not a rational function.
3. Consider the third function 
, since it is not a function that is the ratio of two polynomials. So, it is not a rational function.
4. Consider the fourth function 
, since it is a function that is the ratio of two polynomials (x+2) and (5x). So, it is a rational function.
So, Option D is the correct answer.
Think about it, 64 band members split equally into 8 rows. Sounds like division, right? If we're going to split them into each row, that would be eight members for each of the eight rows.
So the answer is that 8 members was in each row.
Let p = weight of papaya and g = weight of grapes.
Then (3/4)g = (3/5)p. Since the weight of grapes is x + 28,
(3/4)(x + 28) = (3/5)p. We must solve for x. To do this, mult. both sides by (5/3):
(5/3)(3/4)(x+28) = (5/3)(3/5)p
Then p = (15/9)(x+28), or (after reduction), p = (5/3)(x+28).
