document.write( "Question 638254: Mary is now four times as her daughter.four years ago the product of their ages was 40 find their present ages. Thankyou \n" ); document.write( "

Algebra.Com's Answer #402083 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"+m+\"$ = Mary's age now
\n" ); document.write( "Let $\"+d+\"$ = Daughter's age now
\n" ); document.write( "given:
\n" ); document.write( "(1) $\"+m+=+4d+\"$
\n" ); document.write( "(2) $\"+%28+m+-+4+%29%2A%28+d+-+4+%29+=+40+\"$
\n" ); document.write( "------------------------
\n" ); document.write( "Substitute (1) into (2)
\n" ); document.write( "(2) $\"+%28+4d+-+4+%29%2A%28+d+-+4+%29+=+40+\"$
\n" ); document.write( "(2) $\"+4%2A+%28+d+-+1+%29%2A%28+d+-+4+%29+=+40+\"$
\n" ); document.write( "(2) $\"++%28+d+-+1+%29%2A%28+d+-+4+%29+=+10+\"$
\n" ); document.write( "(2) $\"+d%5E2+-d+-+4d+%2B+4+=+10+\"$
\n" ); document.write( "(2) $\"+d%5E2+-+5d+-+6+=+0+\"$
\n" ); document.write( "(2) $\"+%28+d+-+6+%29%2A%28+d+%2B+1+%29+=+0+\"$
\n" ); document.write( " $\"+d+=+6+\"$
\n" ); document.write( " $\"+d+=+-1+\"$
\n" ); document.write( "Daughter's age must be positive, so
\n" ); document.write( "the Daughter is 6
\n" ); document.write( "and, since
\n" ); document.write( "(1) $\"+m+=+4d+\"$
\n" ); document.write( "(1) $\"+m+=+4%2A6+\"$
\n" ); document.write( "(1) $\"+m+=+24+\"$
\n" ); document.write( "The Mother is 24
\n" ); document.write( "--------------
\n" ); document.write( "check answers
\n" ); document.write( "(2) $\"+%28+m+-+4+%29%2A%28+d+-+4+%29+=+40+\"$
\n" ); document.write( "(2) $\"+%28+24+-+4+%29%2A%28+6+-+4+%29+=+40+\"$
\n" ); document.write( "(2) $\"+20%2A2+=+40+\"$
\n" ); document.write( "(2) $\"+40+=+40+\"$
\n" ); document.write( "OK \n" ); document.write( "

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