Solving for a variable in algebraic equations

[woz]

Hello, the teacher gave us this assignment in which we had to separate some variables from equations. (example: E=mc^2 for m -> m=E/c^2). I had trouble with 4 of them (the ones in the attachment), I would appreciate some help, The procedure is really important since I want to learn how to solve them.

 

[enigma]

Hi woz,

While we're waiting for the attachment to get approved...

Why don't you go ahaid and post what you've tried / where you're stuck on them. It'll help us help you.

 

[Zurtex]

9. Do you know how to complete the square?

10. Can you get thins in terms of $\cos \theta$ and apply $\arccos$ to both sides?

11. Simmilar to 10

15. This seems to be a trick question, the equation isn't dependent on m at all

 

[marlon]

the solution in a word doc

regards
marlon