document.write( "Question 1089120: Find the sum of the series
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Algebra.Com's Answer #703478 by ikleyn(52910)\"\" \"About 
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document.write( "Let S = 1+(1+a)/2!+(1+a+a^2)/3!+....infinity\r\n" );
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document.write( "Multiply all and every terms/term by (1-a). You will get\r\n" );
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document.write( "(1-a)*S = \"%281-a%29\" + \"%281-a%5E2%29%2F2%21\" + \"%281-a%5E3%29%2F3%21\" + . . . = \r\n" );
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document.write( "        = \"1+%2B+1%2F2%21+%2B+1%2F3%21+%2B+.+.+.+%29\" - (\"a\" + \"a%5E2%2F2%21\" + \"a%5E3%2F3%21\" + . . .) = \r\n" );
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document.write( "        = \"e\" - \"%28e%5Ea-1%29\" = \"1+%2B+e+-+e%5Ea\".\r\n" );
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document.write( "Hence,  S = \"%281+%2B+e+-+e%5Ea%29%2F%281-a%29\", under the condition a =/= 1.\r\n" );
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document.write( "        At a = 1, then the sum S = 1 + e.\r\n" );
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