document.write( "Question 185080This question is from textbook Prentice Hall Mathematics Algebra 2
\n" ); document.write( ": Having trouble with this question:\r
\n" ); document.write( "\n" ); document.write( "Solve for x. e is a number, not a variable
\n" ); document.write( "2e^(x-2) = e^x + 7\r
\n" ); document.write( "\n" ); document.write( "So far, here is my work. I keep going in circles:
\n" ); document.write( "e^(x-2) = (e^x + 7)/2
\n" ); document.write( "ln(e^(x-2)) = ln((e^x + 7)/2)
\n" ); document.write( "x-2 = ln(e^x + 7) - ln(2)
\n" ); document.write( "I get lost here.
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Algebra.Com's Answer #138865 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
\"2e%5E%28x-2%29+=+e%5Ex+%2B+7+\" Start with the given equation.\r
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\n" ); document.write( "\n" ); document.write( "\"2e%5E%28x%29%2Fe%5E2+=+e%5Ex+%2B+7\" Rewrite \"e%5E%28x-2%29\" as \"e%5E%28x%29%2Fe%5E2\" using the identity \"x%5E%28y-z%29=x%5Ey%2Fx%5Ez\" where \"x%3C%3E0\"\r
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\n" ); document.write( "\n" ); document.write( "\"2e%5E%28x%29+=+e%5Ex%2Ae%5E2+%2B+7%2Ae%5E2\" Multiply EVERY term by the LCD \"e%5E2\" to get rid of the fraction.\r
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\n" ); document.write( "\n" ); document.write( "\"2e%5E%28x%29+-+e%5Ex%2Ae%5E2+=+7%2Ae%5E2\" Subtract \"e%5Ex%2Ae%5E2\" from both sides.\r
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\n" ); document.write( "\n" ); document.write( "\"e%5E%28x%29%282+-+e%5E2%29+=+7%2Ae%5E2\" Factor out the GCF \"e%5Ex\"\r
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\n" ); document.write( "\n" ); document.write( "\"e%5E%28x%29+=+7%2Ae%5E2%2F%282+-+e%5E2%29\" Divide both sides by \"2+-+e%5E2\".\r
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\n" ); document.write( "\n" ); document.write( "\"e%5E%28x%29+=+-9.597\" Evaluate the right side with a calculator. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+ln%28-9.597%29\" Take the natural log of both sides (to eliminate the base \"e\")\r
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\n" ); document.write( "\n" ); document.write( "Since you CANNOT take the natural log of a negative number (well at least for now...), this means that there is no solution. \r
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\n" ); document.write( "\n" ); document.write( "So there are no solutions. I would double check the original problem.\r
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\n" ); document.write( "\n" ); document.write( "As visual confirmation, graph the two expressions \"2e%5E%28x-2%29\" and \"e%5Ex+%2B+7\" and you'll find that they do NOT cross. \r
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\n" ); document.write( "\n" ); document.write( "Note: taking the log of a negative number will give you a complex number, but that's extra information...\r
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