document.write( "Question 1109179: Find 1+2+3+4+...+140, the sum of the first 140 natural numbers \n" ); document.write( "
Algebra.Com's Answer #724190 by Alan3354(69443)\"\" \"About 
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Find 1+2+3+4+...+140, the sum of the first 140 natural numbers
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\n" ); document.write( "1 to 140 is 140 numbers
\n" ); document.write( "1+140 = 141
\n" ); document.write( "2+139 = 141
\n" ); document.write( "etc
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\n" ); document.write( "There are 70 pairs * 141
\n" ); document.write( "--> 141*70 = 9870
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