document.write( "Question 1198930: A man is able to save 50naira of his salary in a particular year. After every year he saved 20naira more the preceding year. How long does it take him to save 4370naira
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Algebra.Com's Answer #832612 by ikleyn(52793) $\"\"$ $\"About$

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\n" ); document.write( "A man is able to save 50naira of his salary in a particular year.
\n" ); document.write( "After every year he saved 20naira more the preceding year.
\n" ); document.write( "How long does it take him to save 4370naira
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document.write( "This problem introduces an arithmetic progression with the first term a= 50\r\n" );
document.write( "and the common difference d = 20.\r\n" );
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document.write( "Then the problem asks you to determine the number of terms such that their sum is 4370.\r\n" );
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document.write( "Use the formula for the sum of arithmetic progression\r\n" );
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document.write( "     = .\r\n" );
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document.write( "In this problem, it takes the form\r\n" );
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document.write( "     = \r\n" );
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document.write( "and gives you this equation\r\n" );
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document.write( "    4370 = (50 + 10(n-1))*n,\r\n" );
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document.write( "Reduce the common factor of 10 in both sides and simplify step by step\r\n" );
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document.write( "    437 = 5n + n^2 - n\r\n" );
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document.write( "    n^2 + 4n - 437 = 0.\r\n" );
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document.write( "Solve using the quadratic formula\r\n" );
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document.write( "     =  = .\r\n" );
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document.write( "There are two roots, one positive and the other negative.\r\n" );
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document.write( "Naturally, you want only positive number of terms  n =  =  = 19.\r\n" );
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document.write( "ANSWER.  It will take him 19 months to get his goal.\r\n" );
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\n" ); document.write( "\n" ); document.write( "For introductory lessons on arithmetic progressions see \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( "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 \"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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