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How many bases of x are there such that the number 663 in base x is prime? Please answer this problem ASAP

 Mar 8, 2019
 #1
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663x  can be written as

 

6(x)^2 + 6x + 3   =

 

(3 * 2)(x)^2 + (3*2)x + 3  =

 

3* (2x^2) + 3 * (2x) + 3  =

 

3 [ 2x^2 + 2x + 1 ]

 

Since 3 is a factor  of 663x.....then this is not prime for any base x  [  where x > 6 ]

 

 

cool cool cool

 Mar 8, 2019

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