Question

Check my answer?
http://prntscr.com/61xuar

Answer 1

Mhm thought I showed you how to do this already :P

Answer 2

But once again, no, remember every x element can only have 1 y element and but there could be a repeat in y elements long as the x element is different

Answer 3

Like the example I showed you previously
{(2,1)(2,4)} - not a function, x is repeated twice
{(2,1),(1,1)} - y repeated twice, is a function

Answer 4

but x isn't repeated

Answer 5

What's wrong in your answer?