document.write( "Question 1163799: Question: \"The sum of 40 terms of a certain arithmetic sequence is 430, while the sum of 60 terms is 945. Determine the nth term of the arithmetic sequence.\"\r
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Algebra.Com's Answer #788024 by MathTherapy(10552)\"\" \"About 
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\n" ); document.write( "Question: \"The sum of 40 terms of a certain arithmetic sequence is 430, while the sum of 60 terms is 945. Determine the nth term of the arithmetic sequence.\"\r
\n" ); document.write( "\n" ); document.write( "How do I approach this problem? I went through the questions that are already answered on this site as well as its Algebra II text book. I am still at a loss.\r
\n" ); document.write( "\n" ); document.write( "Thanks
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Use the following formula for the SUM of an A.P.: \"matrix%281%2C3%2C+S%5Bn%5D%2C+%22=%22%2C+%28n%2F2%29%282a%5B1%5D+%2B+%28n++-++1%29d%29%29\"\r\n" );
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document.write( "                                                  \"matrix%281%2C3%2C+43%2C+%22=%22%2C+4a%5B1%5D+%2B+78d%29\" ------ Multiplying by LCD, 2 ---- eq (i)\r\n" );
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document.write( "                                                  \"matrix%281%2C3%2C+63%2C+%22=%22%2C+4a%5B1%5D+%2B+118d%29\" ------ Multiplying by LCD, 2 ---- eq (ii) \r\n" );
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document.write( "                                                  20 = 40d ------- Subtracting eq (i) from eq (ii)\r\n" );
document.write( "                                                  Common difference, or \"matrix%281%2C8%2C+d%2C+%22=%22%2C+20%2F40%2C+%22=%22%2C+1%2F2%2C+%22%2C%22%2C+or%2C+.5%29\"\r\n" );
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document.write( "                                                  \"matrix%281%2C3%2C+43%2C+%22=%22%2C+4a%5B1%5D+%2B+78%281%2F2%29%29\" ------- Substituting ½ for d in eq (i)\r\n" );
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document.write( "Use the following formula for the nth term of an A.P.:
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