2004 #17 and 25

Fraction fun. Maybe simple enough for the SAT but maybe not.

Difficulty: easy.

Difficulty: Another one of the problems that needs you to manipulate one expression until it looks like another.  Try cubing.

Standard instructions for this series: No calculator allowed. Express answers in reduced form. Rationalize denominators. Radicals must be reduced. All numbers are base ten unless otherwise specified. Do not approximate radicals or π. Leave such answers as 1025π or √39, for example. Source: UVM Math Contest 2004

answer 17, answer 25.