document.write( "Question 1031377: Sally is twice as old as Fred four years ago Sally was three times as old as Fred how old is Sally and Fred now \n" ); document.write( "

Algebra.Com's Answer #646078 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let $\"+s+\"$ = Sally's age now
\n" ); document.write( "Let $\"+f+\"$ = Fred's age now
\n" ); document.write( "------------------------
\n" ); document.write( "(1) $\"+s+=+2f+\"$
\n" ); document.write( "(2) $\"+s+-+4+=+3%2A%28+f+-+4+%29+\"$
\n" ); document.write( "------------------------
\n" ); document.write( "(2) $\"+s+-+4+=+3f+-+12+\"$
\n" ); document.write( "(2) $\"+3f+=+s+%2B+8+\"$
\n" ); document.write( "Plug (1) into (2)
\n" ); document.write( "(2) $\"+3f+=+2f+%2B+8+\"$
\n" ); document.write( "(2) $\"+f+=+8+\"$
\n" ); document.write( "and
\n" ); document.write( "(1) $\"+s+=+2f+\"$
\n" ); document.write( "(1) $\"+s+=+2%2A8+\"$
\n" ); document.write( "(1) $\"+s+=+16+\"$
\n" ); document.write( "---------------------
\n" ); document.write( "Sally is 16 and Fred is 8
\n" ); document.write( "---------------------
\n" ); document.write( "check:
\n" ); document.write( "(2) $\"+s+-+4+=+3%2A%28+f+-+4+%29+\"$
\n" ); document.write( "(2) $\"+16+-+4+=+3%2A%28+8+-+4+%29+\"$
\n" ); document.write( "(2) $\"+12+=+3%2A4+\"$
\n" ); document.write( "(2) $\"+12+=+12+\"$
\n" ); document.write( "OK \n" ); document.write( "

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