document.write( "Question 392612: Find the sum of the first 90 odd numbers \n" ); document.write( "
Algebra.Com's Answer #278679 by richard1234(7193)\"\" \"About 
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There's a well known formula that the sum of the first n odd numbers is n^2 (can you prove it works for all positive n?). Using this, the sum of the first 90 odd numbers is 90^2, or 8100. \n" ); document.write( "
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