Math Help

Hey guys my teacher wants me to solve for X on this one… :slight_smile: Can you guys explain how you would do this? I would appreciate it a lot!

Here is the link of the problems:
http://img410.imageshack.us/img410/4654/mathhwcn0.jpg

If you explain one or two I’ll probably understand how to do them. :slight_smile: Thanks! :be: