http://www.webassign.net/cgi-bin/sym...20-%201%29%5E2

lim

x->1 $\displaystyle \frac{3ax-3a}{2(x-1)}$

^I think the error is here, because if I simplify it, there is no where to do l'hopital.

x->1 $\displaystyle \frac{3a(x-1)}{2(x-1)}$

x->1 $\displaystyle \frac{3a}{2}$