<font face="Garamond" size="+2">


Jim's answer is absolutely correct as far as it went, but you should always rationalize your denominators:


*[Tex \LARGE 4y^{-\frac{4}{7}}=\frac{4}{\sqrt[7]{y^{4}}}]


*[Tex \LARGE \left(\frac{4}{\sqrt[7]{y^{4}}}\right)\left(\frac{\sqrt[7]{y^{3}}}{\sqrt[7]{y^{3}}}\right) = \frac{4\sqrt[7]{y^{3}}}{7}]



John
*[tex \LARGE e^{i\pi} + 1 = 0]
</font>