Does this set of ordered pairs represent a function? why or why not?

{(-1,5), (0, -3), (2,,0), (7,5)}

a. no, because one x-value corresponds to two different y-values.

b. yes, because there are two x-values that are the same.

c. no, because two of the y-values are the same.

d. yes, because every x-value corresponds to exactly one y-value.

Awrestling tournament begins with 128 competitors. in the first round, each competitor has 1 match against another wrestler. the winner of each match moves on to the next round until there is a winner. write a sequence in which the terms represent the number of players still in the tournament at the end of each round. describe the sequence? how many rounds are in the tournament?

This is the number of parts out of 100, the numerator of a fraction where the denominator is 100. submit

With alll of except for the 2 that i did already