Question 1153411:  Joe's father is 4 times as old as joe.6 years from now, Joe's father will be 3 times as old as Joe. How old is each now? 
 Answer by Theo(13342)      (Show Source): 
You can  put this solution on YOUR website! x = joes's age now. 
y = joes's father's age now. 
today, joes's father's age is 4 times joe's age. 
you get: 
y = 4x 
in 6 years, joe's father's age will be 3 times joe's age. 
you get: 
y + 6 = 3 * (x + 6) 
simplify to get: 
y + 6 = 3 * x + 18 
subtract 6 from both sides of he equation to get: 
y = 3x + 12 
you have two equations that need to be solved simultaneously. 
they are: 
y = 4x 
y = 3x + 12 
since y = 4x in the first equation, replace y with 4x in the second equation to get: 
4x = 3x + 12 
subtract 3x from both sides of the equation to get: 
x = 12 
that would be joe's age now. 
that makes joe's father's age 4 * 12 = 48 now. 
in 6 years, joe will be 12 + 6 = 18 
in 6 years, joe's father will be 48 + 6 = 54 
54 is equal to 3 * 18. 
requirement of the problem are satisfied. 
the solution is: 
joe is 12 years old and joe's father is 48 years old now. 
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