document.write( "Question 909155: In five years time, Nana's sister will be three times as old as nana. Four years ago, her sister was 6 times as old as her. Find their present ages. \n" ); document.write( "

Algebra.Com's Answer #551642 by clearblueskai(22) $\"\"$ $\"About$

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let x = Nana's present age
\n" ); document.write( "y = her sister's present age \r
\n" ); document.write( "\n" ); document.write( "in five years time:
\n" ); document.write( "x+5 = Nana's age
\n" ); document.write( "y+5 = her sister's age
\n" ); document.write( " $\"y%2B5+=+3%28x%2B5%29\"$ \r
\n" ); document.write( "\n" ); document.write( "fours years ago:
\n" ); document.write( "x-4 = Nana's age
\n" ); document.write( "y-4= her sister's age
\n" ); document.write( " $\"y-4=6%28x-4%29\"$ \r
\n" ); document.write( "\n" ); document.write( "Equations:
\n" ); document.write( " $\"y%2B5=+3%28x%2B5%29\"$ = $\"y-3x-10=0\"$
\n" ); document.write( " $\"y-4=6%28x-4%29\"$ = $\"y-6x%2B20\"$
\n" ); document.write( "Elimination:
\n" ); document.write( " $\"y-3x-10=0\"$ + $\"-y%2B6x-20\"$ = $\"3x-30=0\"$
\n" ); document.write( " $\"x=10\"$
\n" ); document.write( " $\"y%2B5=3%2810%2B5%29\"$
\n" ); document.write( " $\"y%2B5=30%2B15\"$
\n" ); document.write( " $\"y=40\"$ \r
\n" ); document.write( "\n" ); document.write( "Nana: 10 years old Her sister: 40 years old\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

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