Ok we have to graph a step function. I am given y=[-5x]. How do I write the chart for this in order to graph it?

in order to graph a step function/greatest integer function,, you need values of x (not only integers but also with decimal), for example,

if x=3, y=-5(3)=-15 ==> no problem since -15 is an integer
if x=3.1, y=-5(3.1)=-15.5 ==>if not an integer, get the greatest integer preceding the number, in this case -16 (-16 comes before -15.5), thus y=-16
if x=-2.5, y=-5(-2.5) ==>12.5 ==>greatest integer preceding this is 12 (12 comes before 12.5), thus y=12

i think you must try several values of x, then plot it until you see the pattern,, just remember that y values should be integer,,

i hope i was able to help you.. =)