document.write( "Question 1094688: Find the indicated sum.\r
\n" ); document.write( "\n" ); document.write( "5, 15, 45, 135, 405, . . . ; S14 \n" ); document.write( "
Algebra.Com's Answer #709244 by Edwin McCravy(20056)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "Starting with the 2nd term divide each term by the preceding term:\r\n" );
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document.write( "15/5 = 3\r\n" );
document.write( "45/15 = 3\r\n" );
document.write( "135/45 = 3\r\n" );
document.write( "405/135 = 3\r\n" );
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document.write( "Since they are all the same, that shows that it is a geometric series \r\n" );
document.write( "with first term a1 = 5, common ratio r = 3, and number of terms n = 14.\r\n" );
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document.write( "The formula for the sum Sn of a geometric series with first \r\n" );
document.write( "term a1, common ratio r, and number of terms n is:\r\n" );
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document.write( "\"S%5Bn%5D\"\"%22%22=%22%22\"\"a%5B1%5D%28r%5En-1%29%2F%28r-1%29\"\r\n" );
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document.write( "Plugging in a1 = 5, r = 3, and n = 14 into the formula:\r\n" );
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document.write( "\"S%5B14%5D\"\"%22%22=%22%22\"\"%285%29%283%5E14-1%29%2F%283-1%29\"\r\n" );
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document.write( "You simplify that.  The answer is an 8-digit number\r\n" );
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document.write( "Edwin
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