document.write( "Question 121550: im not very good at algebra. Joe's dad s 2 times joe's age. 7 years ago, he was 3 times older than joe. find both's ages. \n" ); document.write( "
Algebra.Com's Answer #89204 by Earlsdon(6294)![]() ![]() ![]() You can put this solution on YOUR website! Let D = Dad's present age and J = Joe's present age. \n" ); document.write( "From the problem description you can write: \n" ); document.write( "D = 2J \"Dad is two times Joe's age\". Substitute this value of D into the second equation and solve for J. \n" ); document.write( "D-7 = 3(J-7) \"Seven years ago (that's -7), Dad was three times Joe's age\". \n" ); document.write( "2J-7 = 3(J-7) Simplify. \n" ); document.write( "2J-7 = 3J-21 Subtract 2J from both sides. \n" ); document.write( "-7 = J-21 Add 21 to both sides. \n" ); document.write( "14 = J \n" ); document.write( "Joe's age is 14 \n" ); document.write( "D = 2J \n" ); document.write( "D = 2(14) \n" ); document.write( "D = 28 \n" ); document.write( "Dad's age is 28 \n" ); document.write( " |