Find the Laurent series, valid in the annulus $\displaystyle (z:\frac{1}{2} < |z| < 2)$

for

$\displaystyle \frac {1}{(2z-1)(z-2)}$

Find the Taylor series, centered at $\displaystyle z=1$

of

$\displaystyle \frac{1}{(z+1)(z-2)}$

What is the radius of convergence of this series?