document.write( "Question 985848: Help pls 😊
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document.write( "Triangular numbers are: 1,3,6,10....where the nth such number is n(n-1)/2. Show that the sum of two consecutive triangular numbers is a square number. \n" );
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Algebra.Com's Answer #606671 by Alan3354(69443)![]() ![]() You can put this solution on YOUR website! Triangular numbers are: 1,3,6,10....where the nth such number is n(n-1)/2. Show that the sum of two consecutive triangular numbers is a square number. \n" ); document.write( "------------ \n" ); document.write( "n(n-1)/2 + (n+1)*n/2 = (n^2-n + n^2+n)/2 \n" ); document.write( "= 2n^2/2 \n" ); document.write( "= n^2 \n" ); document.write( " |