document.write( "Question 255252: The difference of the cubes of two consecutive positive integers is 217. What is the sum of the two integers?
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Algebra.Com's Answer #187541 by palanisamy(496)![]() ![]() ![]() You can put this solution on YOUR website! Let the two consecutive integers be n and (n+1) \n" ); document.write( "Given, (n+1)^3-n^3 = 217 \n" ); document.write( " n^3+3n^2+3n+1-n^3-217 = 0 \n" ); document.write( " 3n^2+3n-216 = 0 \n" ); document.write( " n^2+n-72 = 0 \n" ); document.write( " (n+9)(n-8) = 0 \n" ); document.write( " n = 8 or -9 \n" ); document.write( "Taking n =8, we get the numbers are 8and 8+1 = 9 \n" ); document.write( "Sum of the numbers = 8+9 = 17 \n" ); document.write( " |