SOLUTION: factoring: quadratic equations and completing the square a^6-4a^3-21=0

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Question 125902: factoring: quadratic equations and completing the square
a^6-4a^3-21=0
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
a^6-4a^3-21=0
(a^3-7)(a^3+3) = 0
a = cube root of 7 or a = cube root of 3
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Cheers,
Stan H.