document.write( "Question 1207158: Log4x+log4(x-3)=1 find the solution \n" ); document.write( "

Algebra.Com's Answer #844872 by ikleyn(52797) $\"\"$ $\"About$

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\n" ); document.write( "Log4x+log4(x-3)=1 find the solution
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document.write( "Log4x + log4(x-3) = 1\r\n" );
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document.write( "    Assuming that the logarithms are base 4 . . . \r\n" );
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document.write( " +  = 1  \r\n" );
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document.write( " = 1 \r\n" );
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document.write( "x*(x-3) = 4\r\n" );
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document.write( " = 0\r\n" );
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document.write( "Factor left side\r\n" );
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document.write( "(x-4)*(x+1) = 0\r\n" );
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document.write( "Of two roots of the last equation, only x= 4 is the solution to the original equation.\r\n" );
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document.write( "x= -1 does not work, since only positive argument is allowed to logarithm.\r\n" );
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document.write( "ANSWER.  The original equation has a unique solution x= 4 in real numbers.\r\n" );
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