document.write( "Question 562871: Sue is twice as old as Emma and 7 years older than Abby. The sum of their ages is 53. How old is each? \n" ); document.write( "

Algebra.Com's Answer #364717 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"+s+\"$ = Sue's age
\n" ); document.write( "Let $\"+e+\"$ = Emma's age
\n" ); document.write( "Let $\"+a+\"$ = Abby's age
\n" ); document.write( "given:
\n" ); document.write( "(1) $\"+s+=+2e+\"$
\n" ); document.write( "(2) $\"+s+=+a+%2B+7+\"$
\n" ); document.write( "(3) $\"+s+%2B+e+%2B+a+=+53+\"$
\n" ); document.write( "This is 3 equations and 3 unknowns,
\n" ); document.write( "so it's solvable
\n" ); document.write( "---------------
\n" ); document.write( "(2) $\"+s+=+a+%2B+7+\"$
\n" ); document.write( "(2) $\"+a+=+s+-+7+\"$
\n" ); document.write( "and
\n" ); document.write( "(1) $\"+e+=+s%2F2+\"$
\n" ); document.write( "Substitute (1) and (2) into (3)
\n" ); document.write( "(3) $\"+s+%2B+s%2F2+%2B+s+-+7+=+53+\"$
\n" ); document.write( "(3) $\"+%285%2F2%29%2As+-+7+=+53+\"$
\n" ); document.write( "(3) $\"+%285%2F2%29%2As+=+60+\"$
\n" ); document.write( "(3) $\"+5s+=+120+\"$
\n" ); document.write( "(3) $\"+s+=+24+\"$
\n" ); document.write( "and
\n" ); document.write( "(2) $\"+a+=+s+-+7+\"$
\n" ); document.write( "(2) $\"+a+=+24+-+7+\"$
\n" ); document.write( "(2) $\"+a+=+17+\"$
\n" ); document.write( "and
\n" ); document.write( "(1) $\"+e+=+s%2F2+\"$
\n" ); document.write( "(1) $\"+e+=+24%2F2+\"$
\n" ); document.write( "(1) $\"+e+=+12+\"$
\n" ); document.write( "Sue's age is 24
\n" ); document.write( "Emma's age is 12
\n" ); document.write( "Abby's age is 17
\n" ); document.write( "check:
\n" ); document.write( "(3) $\"+24+%2B+12+%2B+17+=+53+\"$
\n" ); document.write( "(3) $\"+53+=+53+\"$
\n" ); document.write( "OK \n" ); document.write( "

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