Which relation is a function? {(8, 1), (4, 1), (0, 1), (–15, 1)}
{(0, 1), (0, 2), (1, 2), (1, 3)}
{(–2, –12), (–2, 0), (–2, 4), (–2, 11)}
{(–4, –6), (–3, –2), (1, –2), (1, 0)}

To check if a relation is a function, given a mapping diagram of the relation, use the following criterion: If each input has only one line connected to it, then the outputs are a function of the inputs. Example: In the following mapping diagram, y is a function of x, but x is not a function of y: Line Test.

Step-by-step explanation:

x=4

step-by-step explanation:

4+n=5

step-by-step explanation:

this is because the four is four hours and the n represents the 1 extra hour over the weekend.

b= i'm srry i don't know that one.

4+n=5 n=1 because if vernon plays 5 hours a week then 4+1=5 hours.

hope this : )