Which of the following is a composite number? 63,1,0,19

Look at the following graph of the given equation. determine whether the equation is a function. explain why or why not.

Two planes leave an airport at the same time, one flying east, the other flying west. the eastbound plane travels 20 mph slower. they are 1600 mi apart after 2 hr. find the speed of each plane.

Any is very appreciated! (picture is provided below)not sure how to do this at all won't lie