Substitution to make an ODE linear.

Hello. I need help with a couple of differential equations. I have no idea where to start. Apparently these are Bernoulli differential equations (I'm not even sure), and on Wikipedia it says to solve them Quote:

"A change of variables is made to transform into a linear first-order differential equation."

How do I change the variables? What's a "linear first-order differential equation" anyway?! How do you solve any of this?

Any help would be really appreciated.

http://img15.imageshack.us/img15/6529/diffequation.jpg