document.write( "Question 1126795: a). In an AP, the first term -5 and the last term is 105. If the sum of these terms is 1550, how many terms are there in the AP?
\n" ); document.write( "b). The first three terms of a G.P are x+1, x+3 and x+8, and find
\n" ); document.write( "i) The value of x
\n" ); document.write( "ii) The common ratio
\n" ); document.write( "iii) The sum of the first 15 terms. \n" ); document.write( "

Algebra.Com's Answer #743130 by ikleyn(52794) $\"\"$ $\"About$

You can put this solution on YOUR website!
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document.write( "The sum of the first n terms of an arithmetic progression (of any arithmetic progression) is\r\n" );
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document.write( "This formula ideally suits to solve the given problem, since the terms   and    are given in the condition.\r\n" );
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document.write( "So, in your case\r\n" );
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document.write( "1550 =  =  = 50n,\r\n" );
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document.write( "which gives you the number of the terms  n =  = 31.\r\n" );
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document.write( "Answer.  There are  31  terms in the given AP.\r\n" );
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\n" ); document.write( "\n" ); document.write( "There is a bunch of lessons on arithmetic progressions in this site:\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
\n" ); document.write( "\n" ); document.write( "    - One characteristic property of arithmetic progressions\r
\n" ); document.write( "\n" ); document.write( "    - Solved problems on arithmetic progressions \r
\n" ); document.write( "\n" ); document.write( "    - Math Olimpiad level problem on arithmetic progression \r
\n" ); document.write( "\n" ); document.write( "    - Mathematical induction and arithmetic progressions\r
\n" ); document.write( "\n" ); document.write( "    - Mathematical induction for sequences other than arithmetic or geometric\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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\n" ); document.write( "\n" ); document.write( "Regarding your second problem in the post, there is A GOLDEN RULE in this forum, which is the policy
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ONE and ONLY ONE problem per post

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