document.write( "Question 603569: What is the sum of 2+4+6+8+10+12 using the formula for the partial sum of arithmetic series? \n" ); document.write( "
Algebra.Com's Answer #380747 by jim_thompson5910(35256)\"\" \"About 
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S = (n*(a1 + an))/2\r
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\n" ); document.write( "\n" ); document.write( "S = (6*(2+12))/2\r
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\n" ); document.write( "\n" ); document.write( "S = 6*14/2\r
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\n" ); document.write( "\n" ); document.write( "S = 84/2\r
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\n" ); document.write( "\n" ); document.write( "S = 42\r
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\n" ); document.write( "\n" ); document.write( "So 2+4+6+8+10+12 = 42
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