document.write( "Question 175313: I need the help on Log\r
\n" ); document.write( "\n" ); document.write( "Use the properties of logarithms to find the exact value of the expression.
\n" ); document.write( "log 21-log 7 the 3's are lower by the G's like an exponent but bottom...
\n" ); document.write( " 3 3
\n" ); document.write( "I came up with the answer 1 is that correct?\r
\n" ); document.write( "\n" ); document.write( "log(4+x)-log(x-5)=log2 I cant find the answer as well.Uhgg\r
\n" ); document.write( "\n" ); document.write( "I do not have these in my book...Help \n" ); document.write( "
Algebra.Com's Answer #130387 by nerdybill(7384)\"\" \"About 
You can put this solution on YOUR website!
The subscript next to log specifies the \"base\".
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\n" ); document.write( "log_3(21)- log_3(7)
\n" ); document.write( "applying \"log rules\":
\n" ); document.write( "log_3(21)- log_3(7) = log_3(21/7) = log_3(3) = 1
\n" ); document.write( "Note: since 3^1 = 3
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\n" ); document.write( "log(4+x)-log(x-5)=log2
\n" ); document.write( "log((4+x)/(x-5))=log2
\n" ); document.write( "(4+x)/(x-5) = 2
\n" ); document.write( "(4+x) = 2(x-5)
\n" ); document.write( "4+x = 2x-10
\n" ); document.write( "4 = x-10
\n" ); document.write( "14 = x
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\n" ); document.write( "To review log rules see:
\n" ); document.write( "http://www.purplemath.com/modules/logrules.htm\r
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