document.write( "Question 175799: Dad's age is equal to the sum of Laura's, Jeri's and Theresa's ages. If Jeri is 4 years older than Theresa and 3 years younger than Laura, and Dad's age is 38, how old is each daughter? \n" ); document.write( "

Algebra.Com's Answer #130907 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"l\"$ = Laula's age
\n" ); document.write( "Let $\"j\"$ = Jeri's age
\n" ); document.write( "Let $\"t\"$ = Theresa's age
\n" ); document.write( "Let $\"d\"$ = Dad's age
\n" ); document.write( "----------
\n" ); document.write( "Given:
\n" ); document.write( "(1) $\"d+=+38\"$
\n" ); document.write( "(2) $\"d+=+l+%2B+j+%2B+t\"$
\n" ); document.write( "(3) $\"j+=+t+%2B+4\"$
\n" ); document.write( "(4) $\"j+=+l+-+3\"$
\n" ); document.write( "-----------
\n" ); document.write( "From (3)
\n" ); document.write( " $\"t+=+j+-+4\"$
\n" ); document.write( "From (4)
\n" ); document.write( " $\"l+=+j+%2B+3\"$
\n" ); document.write( "Now substitute these into (2)
\n" ); document.write( "(2) $\"d+=+l+%2B+j+%2B+t\"$
\n" ); document.write( "(2) $\"38+=+%28j+%2B+3%29+%2B+j+%2B+%28j+-+4%29\"$
\n" ); document.write( " $\"38+=+3j+-+1\"$
\n" ); document.write( " $\"3j+=+38+%2B+1\"$
\n" ); document.write( " $\"j+=+39%2F3\"$
\n" ); document.write( " $\"j+=+13\"$
\n" ); document.write( "and, since
\n" ); document.write( " $\"t+=+j+-+4\"$
\n" ); document.write( " $\"t+=+13+-+4\"$
\n" ); document.write( " $\"t+=+9\"$
\n" ); document.write( "also,
\n" ); document.write( " $\"l+=+j+%2B+3\"$
\n" ); document.write( " $\"l+=+13+%2B+3\"$
\n" ); document.write( " $\"l+=+16\"$
\n" ); document.write( "Laura is 16, Jeri is 13, and Theresa is 9
\n" ); document.write( "check:
\n" ); document.write( "(2) $\"d+=+l+%2B+j+%2B+t\"$
\n" ); document.write( " $\"38+=+16+%2B+13+%2B+9\"$
\n" ); document.write( " $\"38+=+38\"$
\n" ); document.write( "OK \n" ); document.write( "

\n" );