document.write( "Question 604796: A girl's age in 12 years's time is the square of her present age. Fine her present age. \n" ); document.write( "
Algebra.Com's Answer #381416 by alicealc(293)\"\" \"About 
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girl's age in present = x\r
\n" ); document.write( "\n" ); document.write( "\"x+%2B+12+=+x%5E2\"
\n" ); document.write( "\"0+=+x%5E2+-+x+-+12\"
\n" ); document.write( "0 = (x - 4)*(x + 3)
\n" ); document.write( "x - 4 = 0 or x + 3 = 0
\n" ); document.write( "x = 4 or x = -3
\n" ); document.write( "since the age can't be a negative number, we choose x = 4\r
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\n" ); document.write( "\n" ); document.write( "so, at the present, the girl is 4 years old
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