document.write( "Question 304084: Give a counterexample: the square of a number added to the sum of twice the number and 8 is a prime number. \n" ); document.write( "
Algebra.Com's Answer #217846 by vleith(2983)![]() ![]() ![]() You can put this solution on YOUR website! Pick any even number. \n" ); document.write( "Squaring it results in a number that has a factor of 2. \n" ); document.write( "Doubling it and adding 8 also results in a number that has a factor of 2. \n" ); document.write( "So the resulting sum will always have a factor of 2 as well. \n" ); document.write( "And thus cannot be prime.\r \n" ); document.write( "\n" ); document.write( "So pick 2 or 4 or any even number. \n" ); document.write( "And you will have your counter example \n" ); document.write( " \n" ); document.write( " |