Hi, pra20!
What steps have you already taken to solve the problem yourself, please? If you would like to show the steps that you might take to solve the problem, then I'm sure that someone will come along to advise you as to what you did correctly or incorrectly and will work with you to solve the problem correctly so that you can also learn how to solve it yourself.
Please also click on the following link to read the announcement about homework help here.
Ask Me Help Desk - Announcements in Forum : Homework Help
Thanks!