SOLUTION: How I factor x^4-2x^3-8x+16

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Question 325011: How I factor x^4-2x^3-8x+16
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
+graph%28+300%2C+300%2C+-5%2C+5%2C+-5%2C+5%2C+x%5E4-2x%5E3-8x%2B16%29+
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Hint : x=2 is the only real root.
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Polynomial long division yields,
%28x%5E4-2x%5E3-8x%2B16%29%2F%28x-2%29=x%5E3-8
A difference of two cubes factors,
x%5E3-8=%28x-2%29%28x%5E2%2B2x%2B4%29
So then putting it all together,
x%5E4-2x%5E3-8x%2B16=%28x-2%29%5E2%28x%5E2%2B2x%2B4%29