document.write( "Question 814632: if 3^(8n+3) divided by 5 what will be the remainder,where n is a integer
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Algebra.Com's Answer #515304 by Edwin McCravy(20056)\"\" \"About 
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if 3^(8n+3) divided by 5 what will be the remainder,where n is a integer
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document.write( "If n=1, we have \"3%5E%288%2A1%2B3%29\" = \"3%5E11\" = 177147, when divided by 5, has remainder 2.\r\n" );
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document.write( "That is \"3%5E11+=+5%2A35429+%2B+2\"\r\n" );
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document.write( "We will try to prove, by induction, that the remainder will always be 2.\r\n" );
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document.write( "That is, we will try to prove \"3%5E%288n%2B3%29+=+5%2Ap+%2B+2\" for some integer p\r\n" );
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document.write( "Assume that for all \"n+%3C=+k\", \r\n" );
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document.write( "(1)      \"3%5E%288n%2B3%29+=+5%2Ap+%2B+2\" for some integer p       <--assumed\r\n" );
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document.write( "we want to use (1) to prove: \r\n" );
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document.write( "         \"3%5E%288%28n%2B1%29%2B3%29+=+5%2Aq+%2B+2\" for some integer q   <--unproved \r\n" );
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document.write( "or\r\n" );
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document.write( "         \"3%5E%288n%2B8%2B3%29+=+5%2Aq+%2B+2\" for some integer q     <--unproved\r\n" );
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document.write( "or\r\n" );
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document.write( "(2)     \"3%5E%288n%2B11%29+=+5%2Aq+%2B+2\" for some integer q       <--unproved\r\n" );
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document.write( "We want to show that the assumption of (1) imples (2)\r\n" );
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document.write( "Multiply both sides of (1) by 3^8\r\n" );
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document.write( "        \"3%5E8%2A3%5E%288n%2B3%29+=+3%5E8%2A5p+%2B+3%5E8%2A2\"\r\n" );
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document.write( "        \"3%5E%288n%2B11%29+=+5%283%5E8p%29+%2B+13122\"\r\n" );
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document.write( "        \"3%5E%288n%2B11%29+=+5%283%5E8p%29+%2B+13120+%2B+2\"\r\n" );
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document.write( "        \"3%5E%288n%2B11%29+=+5%283%5E8p%29+%2B+5%2A2624+%2B+2\" \r\n" );
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document.write( "        \"3%5E%288n%2B11%29+=+5%283%5E8p+%2B+2624%29+%2B+2\"\r\n" );
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document.write( "So we take integer \"q+=+3%5E8p+%2B+2624\" and we have proved (2)\r\n" );
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document.write( "(2)     \"3%5E%288n%2B11%29+=+5%2Aq+%2B+2\" for some integer q\r\n" );
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document.write( "Therefore the remainder is 2 for all n\r\n" );
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document.write( "Edwin
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