Cannot compile equation in LaTeX- Help with code please!

1. Nov 11, 2012

su2111

Hello!
I have been trying to get this equation to work in my LaTeX document, I do not really see any issues with it so if somebody could give some guidance that would be really helpful.

Code:
Code (Text):

{\bf{R}} = \sum_{i=1}^{N}_{{\bf{u}}_{i}}

Thank you

Last edited: Nov 11, 2012
2. Nov 11, 2012

su2111

Sorry! No need for help, I figured out what was wrong!

3. Nov 11, 2012

Arkuski

I had trouble figuring out the dollar signs as well.