Tom's father is 3 times old as Tom.  4 years ago he was 4 times older.  How old is Tom I cannot figure how to set this up and get answer

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Let T be Tom's age and F be his father's age.

Right now F = 3T because father is three times as old as Tom.

Four years ago, their ages were F-4 and T-4.  So:

4 (T-4) = F-4

If you do the math there, you get

4T - 16...

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Let T be Tom's age and F be his father's age.

Right now F = 3T because father is three times as old as Tom.

Four years ago, their ages were F-4 and T-4.  So:

4 (T-4) = F-4

If you do the math there, you get

4T - 16 = F -4

So now you substitute in the value of F that we set up earlier.  And you get

4T - 16 = 3T - 4

So now it's pretty simple.

4T = 16 + 3T - 4

T = 12

So Tom is 12.  His father is 36.

Four years ago, he was 8 and Dad was 32.

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