document.write( "Question 291117: Hello, \r
\n" ); document.write( "\n" ); document.write( "How would I solve the following problem:\r
\n" ); document.write( "\n" ); document.write( "Find a counterexample to the statement: The square of a number added to the sum of three times the number and 7 is a prime number.Justify your solution by supporting it with step by step work\r
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\n" ); document.write( "\n" ); document.write( "This is the answer I came up with not sure it right\r
\n" ); document.write( "\n" ); document.write( "If the number is n, then you mean the statement:\r
\n" ); document.write( "\n" ); document.write( "n^2 + 3n + 7 is prime\r
\n" ); document.write( "\n" ); document.write( "Let n = 3k where k is an integer, i.e. n is a multiple of 3.
\n" ); document.write( "Then the expression becomes\r
\n" ); document.write( "\n" ); document.write( "49k^2 + 21k + 3
\n" ); document.write( "= 3(7k^2 + 3k + 1)\r
\n" ); document.write( "\n" ); document.write( "I am not sure this is right but I did try please let me know thank you so much for your help.
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Algebra.Com's Answer #210588 by Alan3354(69443) $\"\"$ $\"About$

You can put this solution on YOUR website!
One counter example is sufficient:
\n" ); document.write( "9^2 + 3*9 + 7 = 115 which is not prime.
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