document.write( "Question 28685: conjecturea formula for 1*2+2*3+3*4+...+n(n+1). \n" ); document.write( "

Algebra.Com's Answer #15625 by venugopalramana(3286) $\"\"$ $\"About$

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conjecturea formula for 1*2+2*3+3*4+...+n(n+1)=SN
\n" ); document.write( "SN=SIGMA{N(N+1)}=SIGMA(N^2)+SIGMA(N)
\n" ); document.write( "=N(N+1)(2N+1)/6 +N(N+1)/2...I HOPE YOU ARE TAUGHT THESE FORMULAE..IF NOT PLEASE COME BACK ..I SHALL GIVE ANOTHER WAY TO GO ABOUT THIS PROBLEM..
\n" ); document.write( "={N(N+1)/2}{(2N+1)/3 + 1}
\n" ); document.write( "={N(N+1)/2}{(2N+1+3)/3 }
\n" ); document.write( "=={N(N+1)/2}{2(N+2)/3}
\n" ); document.write( "=N(N+1)(N+2)/3\r
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