Divide
(A) $\frac{6 x^{4}-9 x^{2}}{3 x}$ (B) $\frac{x^{3}-3 x^{2}+5 x-6}{x-1}$

Divide.
(a) $\frac{6 x^{4}-9 x^{2}}{3 x}$
(b) $\frac{x^{3}-3 x^{2}+5 x-6}{x-1}$