document.write( "Question 796970: four years ago SOPHIE WAS twice as old as her sister. right now she is 1.5 times older than her sister. how old is sophie right now \n" ); document.write( "

Algebra.Com's Answer #481629 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let $\"+a+\"$ = Sophie's age now
\n" ); document.write( "Let $\"+b+\"$ = her sister's age now
\n" ); document.write( "----------------------------
\n" ); document.write( "(1) $\"+a+-+4+=+2%2A%28+b+-+4+%29+\"$
\n" ); document.write( "(2) $\"+a+=+%283%2F2%29%2Ab+\"$
\n" ); document.write( "-----------------
\n" ); document.write( "Substitute (2) into (1)
\n" ); document.write( "(1) $\"+%283%2F2%29%2Ab+-+4+=+2%2A%28+b+-+4+%29+\"$
\n" ); document.write( "(1) $\"+%283%2F2%29%2Ab+-+4+=+2b+-+8+\"$
\n" ); document.write( "(1) $\"+3b+-+8+=+4b+-+16+\"$
\n" ); document.write( "(1) $\"+b+=+16+-+8+\"$
\n" ); document.write( "(1) $\"+b+=+8+\"$
\n" ); document.write( "and
\n" ); document.write( "(2) $\"+a+=+%283%2F2%29%2A8+\"$
\n" ); document.write( "(2) $\"+a+=+12+\"$
\n" ); document.write( "Sophie is 12 now
\n" ); document.write( "check:
\n" ); document.write( "(1) $\"+a+-+4+=+2%2A%28+b+-+4+%29+\"$
\n" ); document.write( "(1) $\"+12+-+4+=+2%2A%28+8+-+4+%29+\"$
\n" ); document.write( "(1) $\"+8+=+2%2A4+\"$
\n" ); document.write( "(1) $\"+8+=+8+\"$
\n" ); document.write( "OK
\n" ); document.write( " \n" ); document.write( "

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