Question 1012804
A father is three times as old as his son 5 years ago fathers age was four times his son age then find their present ages 
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Equations:
f = 3s
f-5 = 4(s-5)
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Substitute for "f" and solve for "s"::
3s-5 = 4s-20
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Son's age = 15 yrs
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Solve for "f"::
f = 3s
Father's age = 3*15 = 45 yrs
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Cheers,
Stan H.
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