SOLUTION: Factor completely. If it is prime, say so. x^3-216

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Question 109542: Factor completely. If it is prime, say so.
x^3-216
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Factor completely:
x%5E3-216 Should be able to recognise this as the difference of two cubes!
%28x%29%5E3+-+%286%29%5E3 The difference of two cubes can be factored thus:
A%5E3-B%5E3+=+%28A-B%29%28A%5E2%2BAB%2BB%5E2%29 Applying this to your problem:
%28x%29%5E3-%286%29%5E3+=+%28x-6%29%28x%5E2%2B6x%2B36%29 ...and this is as far as we can factor!