document.write( "Question 916604: Must all be rounded to four decimal places \r
\n" ); document.write( "\n" ); document.write( "9e^19x = 16 ---> 0.0303 \r
\n" ); document.write( "\n" ); document.write( "5(1+10^2x) = 8 ---> 0.006 \r
\n" ); document.write( "\n" ); document.write( "the ones I don't know how to solve are: \r
\n" ); document.write( "\n" ); document.write( "10^(1-x) = 4x \r
\n" ); document.write( "\n" ); document.write( "e^x - 12e^x - 1 = 0 \r
\n" ); document.write( "\n" ); document.write( "Thank you \n" ); document.write( "
Algebra.Com's Answer #556161 by Edwin McCravy(20059)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "Must all be rounded to four decimal places \r\n" );
document.write( "\"9e%5E%2819x%29+=+16\"\r\n" );
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document.write( "\"ln%289e%5E%2819x%29%29+=+ln%2816%29\"\r\n" );
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document.write( "\"ln%289%29%2Bln%28e%5E%2819x%29%29=ln%2816%29\"\r\n" );
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document.write( "\"ln%289%29%2B19x=ln%2816%29\"\r\n" );
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document.write( "\"19x=ln%2816%29-ln%289%29\"\r\n" );
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document.write( "\"x=%28ln%2816%29-ln%289%29%29%2F19\"\r\n" );
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document.write( "\"x=0.0303\"\r\n" );
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document.write( "You got that one correct\r\n" );
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document.write( "\"5%281%2B10%5E%282x%29%29+=+8++%0D%0A%7B%7B%7B5+%2B+5%2A10%5E%282x%29=+8\"\r\n" );
document.write( "\"5%2A10%5E%282x%29=3\"\r\n" );
document.write( "\"log%285%29%2Blog%2810%5E%282x%29%29=log%283%29\"\r\n" );
document.write( "\"log%285%29%2B2x=log%283%29\"\r\n" );
document.write( "\"2x=log%283%29-log%285%29\"\r\n" );
document.write( "\"x+=+%28log%283%29-log%285%29%29%2F2\"\r\n" );
document.write( "\"x+=+-.1109\"\r\n" );
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document.write( "Oh! oh!, you missed that one.  Use \"log\" not \"ln\"\r\n" );
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document.write( "\"10%5E%281-x%29+=+4x\"\r\n" );
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document.write( "That one cannot be solved using algebra.  You can only\r\n" );
document.write( "do it with a graphing calculator.  That's because if\r\n" );
document.write( "a variable is both part of an exponent and also part od\r\n" );
document.write( "something that is not an exponent, then there is no algebraic\r\n" );
document.write( "method for solving it.  The calculator can do, but it\r\n" );
document.write( "essentially does by trial and error, trying answers that get\r\n" );
document.write( "closer and closer to solving it and giving the closest one\r\n" );
document.write( "it can find. \r\n" );
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document.write( "With a graphing calculator, the solution is\r\n" );
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document.write( "x = 0.6115 \r\n" );
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document.write( "-----------------------------\r\n" );
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document.write( "\"e%5Ex+-+12e%5Ex+-+1+=+0\"\r\n" );
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document.write( "The first two terms on the left are like terms,\r\n" );
document.write( "(since both have ex ans 1-12 = -11)\r\n" );
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document.write( "\"1e%5Ex+-+12e%5Ex+-+1+=+0\"\r\n" );
document.write( "\"-11e%5Ex+-+1+=+0\"\r\n" );
document.write( "\"-11e%5Ex+=+1\"\r\n" );
document.write( "\"e%5Ex+=+-1%2F11\"\r\n" );
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document.write( "There is no solution because \"e\" raised to any power is \r\n" );
document.write( "always positive and therefore can never equal a negative \r\n" );
document.write( "number.  Did you copy the problem wrong?\r\n" );
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document.write( "Edwin
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