Question

Which set of ordered pairs represents y as a function of x?
Responses
A {(0, 4), (0, 7), (0, 0), (0, -6)}{(0, 4), (0, 7), (0, 0), (0, -6)}
B {(0, 7), (-2, 6), (-3, 1), (-1, 1)}{(0, 7), (-2, 6), (-3, 1), (-1, 1)}
C {(-8, 4), (-7, 9), (-7, 1), (-3, -1)}{(-8, 4), (-7, 9), (-7, 1), (-3, -1)}
D {(-1, 4), (-7, 9), (3, 6), (-7, -1)}

Answer 1

B

Each x-value must have only one y-value. In B the x-values 0, -2, -3, -1 are all distinct, so y is a function of x. The other choices have repeated x-values with different y-values.