SOLUTION: How can you simplify radicals?

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Question 134104: How can you simplify radicals?
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!
Perform a prime factorization of the quantity under the radical. If any of the prime factors occur in pairs, remove the pair from under the radical and put a single instance of the factor outside the radical. Once all the pairs have been removed, re-combine the remaining factors under the radical, and combine any factors you have moved outside of the radical.

Example: sqrt%2897020%29

97020/2 = 48510 One factor of 2, still even
48510/2 = 24255 Another factor of 2, no longer even, but sum of digits div by 3
24255/3 = 8085 One factor of 3, sum of digits still div by 3
8085/3 = 2695 Another factor of 3, sum of digits not div by 3, but ends in 5
2695/5 = 539 One factor of 5, Does not end in 5, so try 7
539/7 = 77 One factor of 7
77/7 = 11 Another factor of 7
11 Is prime.

Factors: 2 * 2 * 3 * 3 * 5 * 7 * 7 * 11.

Pair of 2s, pair of 3s, and pair of 7s, so

sqrt%2897020%29=2%2A3%2A7%2Asqrt%285%2A11%29=42%2Asqrt%2855%29. And that is as simple as you can make it.

Example 2:

sqrt%28x%5E3-7x%5E2%2B16x-12%29

x%5E3-7x%5E2%2B16x-12 divided by x-3 = x%5E2-4x%2B4 (use synthetic division to verify this for yourself). And x%5E2-4x%2B4 factors to %28x-2%29%28x-2%29, so:

sqrt%28x%5E3-7x%5E2%2B16x-12%29=sqrt%28%28x-2%29%5E2%28x-3%29%29=%28x-2%29sqrt%28x-3%29