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)![]() ![]() You can put this solution on YOUR website! . \n" ); document.write( "S=sister's age; F=Fred's age=3S \n" ); document.write( ". \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. \n" ); document.write( ". \n" ); document.write( "CHECK: \n" ); document.write( ". \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 \n" ); document.write( " |