# SOLUTION: John is twice as old as his brother. Four years ago, he was four times as old as his brother. find their present ages.

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 Question 308656: John is twice as old as his brother. Four years ago, he was four times as old as his brother. find their present ages.Answer by rapaljer(4667)   (Show Source): You can put this solution on YOUR website!Let x= brother's age now 2x = John's age now x-4 = brother's age 4 years ago 2x-4 = John's age 4 years ago The EQUATION: John's age 4 years ago was four times the brother's age 4 years ago. 2x-4=4(x-4) 2x-4=4x-16 Subtract 2x from each side: 2x-2x-4=4x-2x-16 -4= 2x-16 Add + 16 to each side: 16-4=2x-16+16 12=2x x=6 Check: Brother = 6 now John = 12 now Four years ago, John was 8 and Brother was 2, which is 4 times as old. Dr. Robert J. Rapalje, Retired