document.write( "Question 380157: Find the sum of the first n terms of the following arithmetic sequence.\r
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document.write( "a1 = 2, d = 2; n = 5. \n" );
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Algebra.Com's Answer #269828 by rfadrogane(214)![]() ![]() You can put this solution on YOUR website! Find the sum of the first n terms of the following arithmetic sequence.\r \n" ); document.write( "\n" ); document.write( "a1 = 2, d = 2; n = 5. \n" ); document.write( " Sol'n: \n" ); document.write( " \n" ); document.write( " S = n/2[2a1+(n-1)d] \n" ); document.write( " = (5/2)[2(2)+(5-1)2] \n" ); document.write( " = (5/2)[4+8] \n" ); document.write( " = (5/2)(12) \n" ); document.write( " S = 30 --answer \n" ); document.write( " \n" ); document.write( " |