I need an answer for this, quickly! The test will be over soon and I have no idea what I'm doing. No explanation needed, the marking period is over after today.

Determine whether the set of whole numbers is closed under addition. explain why the set is or is not closed. give an example.

Which is the graph of f(x) = (4)x? image for option 1 image for option 2 image for option 3 image for option 4

Use the four functions below for this question. compare and contrast these four functions using complete sentences focus on the slope and y- intercept first, and then on any additional properties of each function