Constitutional Law help

I have been stuck on these three questions for days and i'm not sure where to go to find them, the textbook I have is no help!!! PLEASE HELP!!!!!

1.I need two resons why amending the U.S constitution would be necessary versus passing a law including the Marbury v.Madison case and the U.S Term limits v Thorton case.. I am stuck and my text book is no help.

2. name and explain 3 necessary elements that you must consider before drafting language to amend the U.S consstitution.

3.list the two primary paths you would pursue to ammend the U.S constitution. (cite the applicable section(s) used.)