Equation not displaying correctly

Just a quick question about equations. I have been trying to get my equations to display correctly but so far no luck.

What I require is this

What I am getting

With this code

$$\label{eq:dn1} \frac{d{N_{1}}}{dt}=-R_{p}+\frac{\phi D}{2L_{crystal}}+N_{2}W_{21}+N_{3}W_{31}+N_{4}W_{41}+C_{up}N_{2}^{2}$$


Also, I can't remember how to make it so all the equation numbers are in the same position on the right hand side of the page. As you can see, this isn't happening either. Usually when I use equations, I don't normally have this problem.

Any help is greatly appreciated.

• Your equation compiles fine. Oct 3 '13 at 0:53
• hmmm interesting I just put that into a quick template using texmaker with the usual packages (amsmath etc) and it still doesn't work. The error I keep receiving is that i've missed a \$ somewhere but as it's within equation, I don't need this. Got me stumped on this one. Oct 3 '13 at 1:30

$$\label{eq:dn1} % \frac{d{N_{1}}}{dt}=-R_{p}+\frac{\phi D}{2L_{crystal}}+N_{2}W_{21}+N_{3}W_{31}+N_{4}W_{41}+C_{up}N_{2}^{2} %$$