Which relation is not a function
a.){(4,5), (-2,3), 0,-9), (2,4)}

b.) {(−1,2), (0,5), (-1,0), (2,-2)}

c.) {(6,7), (8,9), (−3,6), (3,4)}

d.) {(2,4), (1,3), (9,5), (4,7)}

By definition a function can have only one value of y for any given value of x.

Since B. contains both (-1,2) and (-1,0), y has two values for the same value of x and thus B. cannot be a function...

-7.89, -5.23, -5.22, 34.98, 51.02, 51.22

Lets break it down:
(Rational numbers consist of whole, numbers, integers, and fractions)
Negatives come after 0, so the greater the number gets, the less value it has, opposite of positive numbers.
So since -7.89 is the greatest negative number, it will have the least value.

Hope this helps!