document.write( "Question 760453: in 8 years he will be 5 times as old as he was 12 years ago. how old is he now?
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Algebra.Com's Answer #462637 by aquacean(7)![]() ![]() You can put this solution on YOUR website! Methods: \n" ); document.write( "a. \"scratchpad\" \n" ); document.write( "b. \"orthodox\" (algebra stuff)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "A.\r \n" ); document.write( "\n" ); document.write( "8 + 12 = 20 \n" ); document.write( "20 / 4 = 5 \n" ); document.write( "5 * 5 = 25 \n" ); document.write( "25 - 8 = 17\r \n" ); document.write( "\n" ); document.write( "I added 8 years after and 12 years before (which sums uo to 20) to find out how many years it take for him to be five times his age. I divided 20 by 4 (which equated to 5) as 20 is 4/5 of his age 8 years after. And since 20 is 4/5 of his age 8 years after, the other 1/5 is 5. 25 is his age 8 years after. Subtract 8 then you get his present age now which is 17. \r \n" ); document.write( "\n" ); document.write( "B. (This is the \"formal\" solution teachers accept) \n" ); document.write( "a = his present age\r \n" ); document.write( "\n" ); document.write( "a = 5((12 + 8)/4) - 8 \n" ); document.write( "a = 5(20/4) - 8 \n" ); document.write( "a = 25 - 8 \n" ); document.write( "a = 17 \n" ); document.write( " |