document.write( "Question 561142: a mother is 20 years older than her daughter. in 7 years the mother will be 3 times as old as her daughter, how old are they \n" ); document.write( "

Algebra.Com's Answer #364171 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"+m+\"$ = Mother's age now
\n" ); document.write( "Let $\"+d+\"$ = Daughter's age now
\n" ); document.write( " $\"+m+%2B+7+\"$ = Mother's age in 7 years
\n" ); document.write( " $\"+d+%2B+7+\"$ = Daughter's age in 7 years
\n" ); document.write( "given:
\n" ); document.write( "(1) $\"+m+=+d+%2B+20+\"$
\n" ); document.write( "(2) $\"+m+%2B+7+=+3%2A%28+d+%2B+7+%29+\"$
\n" ); document.write( "-----------------------
\n" ); document.write( "(2) $\"+m+%2B+7+=+3d+%2B+21+\"$
\n" ); document.write( "(2) $\"+m+-+3d+=+14+\"$
\n" ); document.write( "and
\n" ); document.write( "(1) $\"+m+-+d+=+20+\"$
\n" ); document.write( "Subtract (2) from (1)
\n" ); document.write( "(1) $\"+m+-+d+=+20+\"$
\n" ); document.write( "(2) $\"+-m+%2B+3d+=+-14+\"$
\n" ); document.write( " $\"+2d+=+6+\"$
\n" ); document.write( " $\"+d+=+3+\"$
\n" ); document.write( "and, since
\n" ); document.write( "(1) $\"+m+=+d+%2B+20+\"$
\n" ); document.write( "(1) $\"+m+=+3+%2B+20+\"$
\n" ); document.write( "(1) $\"+m+=+23+\"$
\n" ); document.write( "The Mother is 23 and the Daughter is 3
\n" ); document.write( "check:
\n" ); document.write( "(2) $\"+m+%2B+7+=+3%2A%28+d+%2B+7+%29+\"$
\n" ); document.write( "(2) $\"+23+%2B+7+=+3%2A%28+3+%2B+7+%29+\"$
\n" ); document.write( "(2) $\"+30+=+30+\"$
\n" ); document.write( "OK \n" ); document.write( "

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