√25 + 5√4 + 5√5. notice that 25 and 4 are perfect squares because their square roots are integers. 5 + (5)(2) + 5√5. 5 + 10 + 5√5. 15 + 5√5.
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when there is no radical in the denominator.
http://wiki.answers.com/Q/When_is_a_radical_in_sim...

1. Compare the radical expressions to see if they represent the same root. For example, √5 and √8 are both square roots. If either expression had a superscript number
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You find the simplest form of a radical through taking it's square
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