document.write( "Question 108092: in need of help with:solve algebraically ln 2+ ln(x-6)=ln(x+2) \n" ); document.write( "
Algebra.Com's Answer #78750 by bucky(2189)\"\" \"About 
You can put this solution on YOUR website!
Given:
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\n" ); document.write( "\"ln%282%29+%2B+ln%28x-6%29+=+ln%28x%2B2%29\"
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\n" ); document.write( "By the rules of logarithms, when you add to logarithms it is equivalent to the logarithm
\n" ); document.write( "of their product. Therefore, the left side of the given equation can be changed as indicated
\n" ); document.write( "below:
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\n" ); document.write( "\"ln%282%2A%28x-6%29%29+=+ln%28x%2B2%29\"
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\n" ); document.write( "Look carefully at this equation. Both sides have the natural logarithm of a quantity.
\n" ); document.write( "So for the equation to be true, the quantities on which the logarithm operates have to
\n" ); document.write( "be equal. This being the case, then we can say:
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\n" ); document.write( "\"2%2A%28x-6%29\" must equal \"%28x%2B2%29\"
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\n" ); document.write( "so that in the given equation the natural logarithm operator is acting on two equal quantities.
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\n" ); document.write( "Now we can work on solving for x by solving the equation:
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\n" ); document.write( "\"2%2A%28x-6%29+=+x%2B2\"
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\n" ); document.write( "Multiplying out the left side changes this equation to:
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\n" ); document.write( "\"2x+-+12+=+x+%2B+2\"
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\n" ); document.write( "Get rid of the 12 on the left side by adding 12 to both sides of this equation to get:
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\n" ); document.write( "\"2x+=+x+%2B+2+%2B+12\"
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\n" ); document.write( "Next get rid of the x on the right side by subtracting x from both sides to reduce the
\n" ); document.write( "equation to:
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\n" ); document.write( "\"x+=+2+%2B+12+=+14\"
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\n" ); document.write( "So the answer to this problem is x = 14.
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\n" ); document.write( "You can check this answer by returning to the given problem. Substituting 14 for x in the
\n" ); document.write( "given equation results in:
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\n" ); document.write( "\"ln%282%29+%2B+ln%2814-6%29+=+ln%2814+%2B+2%29\"
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\n" ); document.write( "This simplifies to:
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\n" ); document.write( "\"ln%282%29+%2B+ln%288%29+=+ln%2816%29\"
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\n" ); document.write( "At this point you can use a calculator to look up each of these three natural logarithms.
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\n" ); document.write( "ln(2) = 0.69314718
\n" ); document.write( "ln(8) = 2.079441542
\n" ); document.write( "ln(16) = 2.772588722
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\n" ); document.write( "Substituting these values for the natural logarithms of the equation results in:
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\n" ); document.write( "\"0.69314718%2B2.079441542=2.772588722\"
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\n" ); document.write( "When you complete the addition on the left side you get:
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\n" ); document.write( "\"2.772588722=2.772588722\"
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\n" ); document.write( "This tells you that when x = 14 the equation is correct.
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\n" ); document.write( "\n" ); document.write( "Hope this helps you to understand the problem and the process you can use to find the
\n" ); document.write( "answer for the value of x.
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