document.write( "Question 1073261: Find the sum of first 20 term of the series 1+1+2÷2+1+2+3÷3+1+2+3+4÷4.... \n" ); document.write( "
Algebra.Com's Answer #688105 by Edwin McCravy(20056)![]() ![]() You can put this solution on YOUR website! \r\n" ); document.write( "1+1+2÷2+1+2+3÷3+1+2+3+4÷4....\r\n" ); document.write( "\r\n" ); document.write( "Separate it into groups to get the pattern\r\n" ); document.write( "\r\n" ); document.write( "1 + 1+2÷2 + 1+2+3÷3 + 1+2+3+4÷4....\r\n" ); document.write( "\r\n" ); document.write( "Extend the pattern until there are 20 numbers\r\n" ); document.write( "(we get the 20th number just as it bwgins the \r\n" ); document.write( "last group):\r\n" ); document.write( "\r\n" ); document.write( "1 + 1+2÷2 + 1+2+3÷3 + 1+2+3+4÷4 + 1+2+3+4+5÷5 + 1\r\n" ); document.write( "\r\n" ); document.write( "We do divisions first, and they're all 1's: \r\n" ); document.write( "\r\n" ); document.write( "1 + 1+1 + 1+2+1 + 1+2+3+1 + 1+2+3+4+1 + 1\r\n" ); document.write( "\r\n" ); document.write( "1 + 2 + 4 + 7 + 11 + 1\r\n" ); document.write( "\r\n" ); document.write( "Answer: 26 \r\n" ); document.write( "\r\n" ); document.write( "Edwin\n" ); document.write( " |