Question

http://prntscr.com/djxw2w

Answer 1

@phillthechill

Answer 2

only a

Answer 3

you see because they repeat in b

Answer 4

oh yeh

Answer 5

ok

Answer 6

If you think of a graph, doing a vertical line test
it is not a function if one x value, returns two y values

so from your table, you see that in B it has x=7 y=3
x=7, y=2

hence one x value returns two y values, hence B is not a function