1. Which set of ordered pairs is NOT a function? a) {(3,1),(2,1),(1,2),(3,2)}
b) {(4,1),(5,1),(6,1),(7,1)}
c) {(1,2),(3,4),(4,5),(5,6)}
d) {(0,0),(1,1),(2,2),(3,3)}
please help me !!

I think it's a

Step-by-step explanation:

a - many-to-many

b - many-to-one

c - one-to-one

d - one-to-one

1. is 4 and 2. is 3

step-by-step explanation:

so if you look at the first one you see that 1 is to 4 and 2 is to 8 and so on, so you can see for every 1 there is a times 4 so if it were 3 then it would be 3*4 and it is 12

for number 2 it is 3 because 1 is to 3 and 2 is to 6 so for every 1 there is 3 so if it were 3 then there would be 3*3 = 9

19.

step-by-step explanation:

you add the 9 in the tens column since it is a single digit and 9 plus zero is 9 so it is 19