document.write( "Question 321615: carla is four times her daughter's age. in thirty years her daughter will be half as old as carla. how old is carla and her daughter now? \n" ); document.write( "

Algebra.Com's Answer #230295 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"c\"$ = Carla's age now
\n" ); document.write( "Let $\"d\"$ = daughter's age now
\n" ); document.write( "given:
\n" ); document.write( " $\"c+=+4d\"$
\n" ); document.write( " $\"d+%2B+30+=+%281%2F2%29%2A%28c+%2B+30%29\"$
\n" ); document.write( "Multiply both sides by $\"2\"$
\n" ); document.write( " $\"2d+%2B+60+=+c+%2B+30\"$
\n" ); document.write( "By substitution:
\n" ); document.write( " $\"2d+%2B+60+=+4d+%2B+30\"$
\n" ); document.write( " $\"2d+=+60+-+30\"$
\n" ); document.write( " $\"2d+=+30\"$
\n" ); document.write( " $\"d+=+15\"$
\n" ); document.write( "and
\n" ); document.write( " $\"c+=+4d\"$
\n" ); document.write( " $\"c+=+4%2A15\"$
\n" ); document.write( " $\"c+=+60\"$
\n" ); document.write( "Carla is 60 and her daughter is 15
\n" ); document.write( "check:
\n" ); document.write( " $\"d+%2B+30+=+%281%2F2%29%2A%28c+%2B+30%29\"$
\n" ); document.write( " $\"15+%2B+30+=+%281%2F2%29%2A%2860+%2B+30%29\"$
\n" ); document.write( " $\"45+=+%281%2F2%29%2A90\"$
\n" ); document.write( " $\"45+=+45\"$
\n" ); document.write( "OK \n" ); document.write( "

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