document.write( "Question 1158138: The product of the present ages of a mother and her daughter is 432. Four years ago the mother was exactly four times as old as the daughter .what are their present ages? \n" ); document.write( "

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\n" ); document.write( "The product of the present ages of a mother and her daughter is 432. Four years ago the mother was exactly four times as old as the daughter .what are their present ages?
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Let mother's and daughter's ages be M and D, respectively
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document.write( "Then we get: MD = 432 ------ eq (i)
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document.write( "Also, M - 4 = 4(D - 4)____M - 4 = 4D - 16_____M = 4D - 12 ----- eq (ii)
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document.write( "D(4D - 12) = 432 ------ Substituting 4D - 12 for M in eq (i)
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document.write( "(D - 12)(D + 9) = 0
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document.write( "Daughter's age, or        OR      D = - 9 (ignore) \n" );
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