[SOLVED] division of an algebric expression

Please check if this is right:

$\displaystyle \frac {2^{-3}a^ \frac {2}{3} b^4}{2^{-2}a^ \frac {1}{6} b^4}$

$\displaystyle 1^{-3-(-2)} a^{\frac {2}{3}-\frac {1}{6}} b^{4-4}$

$\displaystyle 1^{-1} a^{\frac {4}{6}-\frac {1}{6}}$

$\displaystyle 1 a^{\frac {3}{6}}$

$\displaystyle a^{\frac {3}{6}}$

$\displaystyle a^{\frac {1}{2}}$

$\displaystyle \sqrt{a}$

The exposants can't be fractions for the answer to be right...

(wow this was tough code to write!!!)

I'm really starting to hate math! sorry (Headbang)