document.write( "Question 989154: Fred is 3 times old than his sister. Four years ago he was 5 times as old as his sister. Find their present age. \n" ); document.write( "
Algebra.Com's Answer #609608 by macston(5194)\"\" \"About 
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\n" ); document.write( "S=sister's age; F=Fred's age=3S
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\n" ); document.write( "F-4=5(S-4) Substitute for F.
\n" ); document.write( "3S-4=5S-20
\n" ); document.write( "16=2S
\n" ); document.write( "8=S ANSWER 1: Sister is 8 years old,
\n" ); document.write( "F=3S=3(8)=24 ANSWER 2: Fred is 24 years old.
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\n" ); document.write( "CHECK:
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\n" ); document.write( "F-4=5(S-4)
\n" ); document.write( "24-4=5(8-4)
\n" ); document.write( "20=5(4)
\n" ); document.write( "20=20
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