Which relation is a function?

C

Step-by-step explanation:

if you don't have from same x different outcomes is a function

think that x is a day you count votes, you can not get for the same day different y number of votes ( something is fishy then)

A. not a function because (6, -3) and (6, 3)

B. not  a function because (4,7) and (4,2)

C. is a function

D. not a function because (2, -1) (2,1) (2,3)

51

step-by-step explanation:

73-22=51 the   mass number minus the amount of protons gives you the amount of neutrons

circumference divided by 3.141592654 then timesthe radius twice

step-by-step explanation:

circumference divided by 3.141592654 then timesthe radius twice