What is the value of $x$ if $x=\frac{2009^2-2009}{2009}$?
I notice that the numerator of the fraction is a difference of two terms that both have 2009 as a factor. So I can factor out 2009 from the numerator and simplify the fraction. I get $x=\frac{2009(2009-1)}{2009}=\frac{2009-1}{1}=2008$. 