Quandaries and Queries


my name is JV,

my friend and i were just wondering,

6x to the third power plus 5x plus 15, is that prime or not prime, and whichever it is, how can you prove it? ya dig?


JV from ATL



Hi JV,

It depends on the value of x: With x odd, you get an even number, which is not prime. With x a multiple of 3 or 5, you get a multiple of 3 or 5 respectively. With x = 2 you get 73 which is prime, and with x = 4 you get 419, prime. However with x = 8, you get 3127 = 53*59, And with x = 16, you get 24671, again prime.


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