Best answer gets

hank is throwing a surprise party. the party costs $20 per person. create an equation and graph to represent the relationship between the cost of the party and the number of friends attending.

complete the following table:

number of friends (f) 5 10 15 20
cost of party (c) 100 200 300 400

plots the points from the table onto the graph.

The equation would be y=x+20
I can't exactly draw a table right now but all you would need to do is put the numbers in the table format and (if you need to add more) add 100 for every f increase of 5. E.x. 25 (f value) would make 500 (c value.)
To plot the points, just use the f value as the x and c value as the y (x,y) becomes (f,c). Then just label the x axis and y axis accordingly, using friends as the x and cost as the y. Hope this helps