How to solve math placement test questions #14 and #15?

[ussjt]

I am getting ready to take my placement test for college, but it has been over a year since I have taken math. So could some one explain to me, in step by step form, how to solve #14 and #15.
http://www.math.ohio-state.edu/counseling/imgs/D-Test02.jpg

here are the answers:
http://www.math.ohio-state.edu/counseling/imgs/D-Test_Answers04.gif

Thanks for any help.

 

[dextercioby]

I'm sorry, we don't do that here. We're waiting for the OP to draw the first blood. As an advice, never apprach any exercise without mastering the theory behind it.

Daniel.

P.S.Next time, post in the Homework section (it looks like HS to me) after having read the guidelines atop the HS homework help forum.

 

[ussjt]

sorry, I was not sure what section to put it in. If someone could please move it, then that would be great.


About the problems...the only real question I have is what does the "i" symbol stand for. I remember seeing it before, but no one can seem to remember what it is.

 

[Jameson]

"i" is usually defined as \sqrt{-1}