document.write( "Question 735805: ln(4x-5)+ln(x-3)=ln15 \n" ); document.write( "

Algebra.Com's Answer #450537 by Susan-math(40) $\"\"$ $\"About$

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Use the rule $\"lna+%2B+ln+b+=+ln%28ab%29\"$ \r
\n" ); document.write( "\n" ); document.write( "so $\"ln%284x-5%29%2Bln%28x-3%29=ln%28%284x-5%29%28x-3%29%29\"$ \r
\n" ); document.write( "\n" ); document.write( "so now you have
\n" ); document.write( " $\"ln%28%284x-5%29%28x-3%29%29=ln15\"$
\n" ); document.write( "so $\"%284x-5%29%28x-3%29=15\"$
\n" ); document.write( " $\"4x%5E2-5x-12x%2B15=15\"$
\n" ); document.write( " $\"4x%5E2-17x=0\"$
\n" ); document.write( " $\"x%284x-17%29=0\"$
\n" ); document.write( " $\"x=0\"$ or $\"x=17%2F4\"$ \r
\n" ); document.write( "\n" ); document.write( "but must omit x=0 since it has us take ln of a negative number when substituted into 4x-5 or x-3, so it is not in the domain. \r
\n" ); document.write( "\n" ); document.write( "so answer is x=17/4 \n" ); document.write( "

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