Assistance with math problem

I'm going to remind you again of possible copyright issues with the number of math questions you are publicizing here on AN. Directly from the terms of service you agreed to when signing up:

6. You agree NOT to post any copyrighted material.

That said, have you made an appointment to sit down with your instructor? With the number of questions you have brought here, that would be wise. There is only so much help an online message board can provide, and if the issue is with the book these questions are coming from, then we cannot help you at all- that is something the professor needs to address.

Just so I don't make the mistake again, which part above is a copy right issue? The question comes from a paper test. Please let me know. The way I worked the problem came from memory - thanks.

The test material is "owned" by the person/organization who wrote, whether that is a test bank provided with a text book or an instructor who wrote the test. This is a quote from sirI, who responded to someone else's similar question quite some time ago:

Under U.S. copyright law regarding Reproduction, individuals cannot copy/reproduce the work by the author. They can either purchase (or in this case, download=lending) a book/article, but cannot reproduce it other than for self.

It is not necessary that the entire original work to be copied for an infringement of the reproduction right to occur. All that is necessary is that the copying be "substantial and material."