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In base $b,$ the square of the number $17_b$ is $211_b$. Find the base $b$.

 Jul 27, 2024
 #1
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17b =   (1b + 7)

 

(1b + 7)^2  =  b^2 + 14b + 49

 

211b  = 2b^2 + 1b + 1

 

 

b^2 + 14b + 49  = 2b^2 + 1b + 1

 

b^2 - 13b - 48 = 0

 

(b - 16) ( b + 3)  = 0

 

b - 16  = 0

 

b = 16

 

cool cool cool

 Jul 28, 2024

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