Which of the sets of ordered pairs represents a function?

a = {(−4, 5), (1, −1), (2, −2), (2, 3)}

b = {(2, 2), (3, −2), (9, 3), (9, −3)}

1. only a
2. only b
3. both a and b
4. neither a nor b

A function WILL NOT have any repeating x values. They can have repeating y values, just not the x ones. So just look at the x values.

so look at x values in  Aare there any repeating x values ? Yes there isthere are repeating 2's...therefore, A is not a function.

now look at the x values in B...are there any repeating x values ? yes there isthere are repeating 9'sso B is not a function.

so neither A or B are functions

If cheese is $4.40 per kilogram, you should pay .88