document.write( "Question 129944: I need help solving this logarithmic equation\r
\n" ); document.write( "\n" ); document.write( "log(x-14)-log5=log(x-12)-logx
\n" ); document.write( "

Algebra.Com's Answer #94888 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
Start with the given equation\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"log%2810%2C%28%28x-14%29%2F5%29%29=log%2810%2C%28%28x-12%29%2Fx%29%29\" Combine the logs using the identity \"log%28b%2C%28A%29%29-log%28b%2C%28B%29%29=log%28b%2C%28A%2FB%29%29\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"%28x-14%29%2F5=%28x-12%29%2Fx\" Raise both sides as exponents with bases of 10 to eliminate the logs on both sides\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"cross%285%29x%28%28x-14%29%2Fcross%285%29%29=5cross%28x%29%28%28x-12%29%2Fcross%28x%29%29\" Multiply both sides by \"5x\" to eliminate the fractions\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x%28x-14%29=5%28x-12%29\" Multiply \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x%5E2-14x=5x-60\" Distribute \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x%5E2-14x-5x%2B60=0\" Subtract 5x from both sides. Add 60 to both sides. \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x%5E2-19x%2B60=0\" Combine like terms\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"%28x-15%29%28x-4%29=0\" Factor the left side (note: if you need help with factoring, check out this solver)\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Now set each factor equal to zero:\r
\n" ); document.write( "\n" ); document.write( "\"x-15=0\" or \"x-4=0\" \r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x=15\" or \"x=4\" Now solve for x in each case\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So our possible answers are \r
\n" ); document.write( "\n" ); document.write( " \"x=15\" or \"x=4\" \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "However, if you plug in \"x=4\" into , you'll get a negative number inside the log. So our only solution is \"x=15\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "-----------------------------------\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Answer:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So our answer is \"x=15\"
\n" ); document.write( "
\n" ); document.write( "
\n" );