document.write( "Question 1118014: Determine the sum of the geometric sequence: 1 + 5 + 25 + ... + 3125. \n" ); document.write( "
Algebra.Com's Answer #733194 by ikleyn(52788)\"\" \"About 
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document.write( "Geometric progression with the first term of 1 and the common ratio of 5.\r\n" );
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document.write( "The number of terms is 6:   \"5%5E%286-1%29\" = \"5%5E5\" = 3125.\r\n" );
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document.write( "Use the formula for the sum of the first n terms of a Geom. progression with the first term a and the common ratio of r:\r\n" );
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document.write( "\"S%5Bn%5D\" = \"%28a%2Ar%5En+-+a%29%2F%28r-1%29\".\r\n" );
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document.write( "Substitute the given values and calculate:\r\n" );
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document.write( "\"S%5B5%5D\" = \"1%2A%285%5E6-1%29%2F%285-1%29\" = 3906.\r\n" );
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\n" ); document.write( "On geometric progressions,  see the introductory lessons\r
\n" ); document.write( "\n" ); document.write( "    - Geometric progressions\r
\n" ); document.write( "\n" ); document.write( "    - The proofs of the formulas for geometric progressions \r
\n" ); document.write( "\n" ); document.write( "    - Problems on geometric progressions\r
\n" ); document.write( "\n" ); document.write( "    - Word problems on geometric progressions\r
\n" ); document.write( "\n" ); document.write( "in this site.\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
\n" ); document.write( "\"Geometric 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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