SOLUTION: solve by factoring given that (x+4) is one factor x^3+4x^2-16x-64=0

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Question 1063520: solve by factoring given that (x+4) is one factor
x^3+4x^2-16x-64=0
Found 2 solutions by josgarithmetic, ikleyn:
Answer by josgarithmetic(39620)   (Show Source): You can put this solution on YOUR website!
Divide by x+4 using synthetic division.
-4    |    1    4    -16    -64
      |         -4   0      64
      |__________________________________
          1    0    -16     0


Equation now can be stated




Answer by ikleyn(52803)   (Show Source): You can put this solution on YOUR website!
.
solve by factoring given that (x+4) is one factor
x^3+4x^2-16x-64=0
~~~~~~~~~~~~~~~~~~~~~~

I can easily do it without this hint, simply applying grouping:

= + = - = = = .

Hence, the original equation has the root x = -4 of multiplicity 2 and the root x = 4.



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