document.write( "Question 206004: Given that log[a]5=0.8271 and log[a]20=1.5395 fing log[a]4 \n" ); document.write( "
Algebra.Com's Answer #155577 by Edwin McCravy(20060)\"\" \"About 
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Given that log[a]5=0.8271 and log[a]20=1.5395 fing log[a]4
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document.write( "Use the two facts:\r\n" );
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document.write( "1. \"4+=+20%2F5\"\r\n" );
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document.write( "2. \"log%28X%2C%28Y%2FZ%29%29=log%28X%2C%28Y%29%29-log%28X%2C%28Z%29%29\"\r\n" );
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document.write( "\"log%28a%2C%284%29%29\" \r\n" );
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document.write( "Replace \"%284%29\" by \"%2820%2F5%29\"\r\n" );
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document.write( "\"log%28a%2C%2820%2F5%29%29\"\r\n" );
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document.write( "Use 2 above with \"X=a\", \"Y=20\", \"Z=5\"\r\n" );
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document.write( "\"log%28a%2C%2820%2F5%29%29=log%28a%2C%2820%29%29-log%28a%2C%285%29%29=1.5395-0.8271=0.7124\" \r\n" );
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document.write( "Edwin
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