Okay to make this easy for the both of us i will attach the graphing part below and color code the question to it graph.
Explanation:
Problem 15 is ( 0,0.5) =Graph color Red
Problem 16 is( 0,0.25) = Graph color Blue
Problem 17 is (0,3) = Graph color Green
Problem 18 is (0,4) = Graph color Purple
I just listed the points in which they past through so it would be easier to plot.
I hope I helped you a lot.
Well let me know when you get this and how you did so I will know if i did it correct.