document.write( "Question 1125756: Mr Lee is now ? years old.his current age is the square of his age twenty years ago .Find the current age of Mr Lee. \n" ); document.write( "

Algebra.Com's Answer #742063 by ikleyn(52795) $\"\"$ $\"About$

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document.write( "x = (x-20)^2\r\n" );
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document.write( "Answer.  x = 25  (obtained mentally).\r\n" );
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document.write( "    x = x^2 - 40x + 400\r\n" );
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document.write( "    x^2 -41x + 400 = 0\r\n" );
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document.write( "    (x-25)*(x-16) = 0\r\n" );
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document.write( "    Of two roots of this quadratic equation  x= 25  and  x= 16  only  x= 25  remains positive \"20 years ago\".\r\n" );
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