document.write( "Question 1108174: find the sum of the first n terms of the arithmetic series
\n" ); document.write( "-10+(-5)+0+5+10 n=19
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Algebra.Com's Answer #723162 by ikleyn(52788)\"\" \"About 
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document.write( "You have an arithmetic progression (AP) with the first term -10 and the common difference 5; the number of terms is 19.\r\n" );
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document.write( "For this data, the formula for the sum is \r\n" );
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document.write( "\"S%5B19%5D\" = \"%28a%5B1%5D+%2B+%28d%2A%28n-1%29%29%2F2%29%2An\" = \"%28-10+%2B+%285%2A18%29%2F2%29%2A19\" = 665.\r\n" );
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\n" ); document.write( "For introductory lessons on arithmetic progression, see the lessons\r
\n" ); document.write( "\n" ); document.write( "    - Arithmetic progressions\r
\n" ); document.write( "\n" ); document.write( "    - The proofs of the formulas for arithmetic progressions \r
\n" ); document.write( "\n" ); document.write( "    - Problems on arithmetic progressions \r
\n" ); document.write( "\n" ); document.write( "    - Word problems on arithmetic progressions\r
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\n" ); document.write( "\n" ); document.write( "Also,  you have this free of charge online textbook in ALGEBRA-II in this site\r
\n" ); document.write( "\n" ); document.write( "    - ALGEBRA-II - YOUR ONLINE TEXTBOOK.\r
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\n" ); document.write( "\n" ); document.write( "The referred lessons are the part of this online textbook under the topic \"Arithmetic progressions\".\r
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\n" ); document.write( "\n" ); document.write( "Save the link to this textbook together with its description\r
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\n" ); document.write( "\n" ); document.write( "Free of charge online textbook in ALGEBRA-II
\n" ); document.write( "https://www.algebra.com/algebra/homework/complex/ALGEBRA-II-YOUR-ONLINE-TEXTBOOK.lesson\r
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\n" ); document.write( "\n" ); document.write( "into your archive and use when it is needed.\r
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