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Help.

NotSoSmart  Dec 8, 2017
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 #1
avatar+81022 
+1

We can use synthetic division for the first

 

- 2  [  -2     - 5       4      2   ]

                   4       2    -12

        __________________

        -2       -1      6    -10

 

The remainder is -10   so the third answer is correct

 

 

x^3  - 4x^2  + x +  26  = 0

-2  is one root

 

Use synthetic division to find the remaining polynomial

 

 

-2   [  1      - 4         1         26   ]

                 - 2        12       -26

      _______________________

         1      -6         13         0

 

The remaining polynomial is    x^2  - 6x  + 13

Complete the square on x  and we have

 

 x^2  - 6x +  9  =   -13 + 9

(x - 3)^2   =  -4             take both roots

 

x - 3 =    ±2i

 

x  =  3 ± 2i      are the other two roots     ...... first answer

 

 

cool cool cool

CPhill  Dec 8, 2017

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