SOLUTION: A father is four times as old as his daughter. Five years ago, he was seven times as old as his daughter. Find the present ages of the father and the daughter

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Question 881210: A father is four times as old as his daughter. Five years ago, he was seven times as old as his daughter. Find the present ages of the father and the daughter
Answer by JulietG(1812) About Me  (Show Source):
You can put this solution on YOUR website!
F = 4D
F-5 = 7(D-5)
Distribute
F-5 = 7D-35
Substitute the value of F from the first equation into the second
4D-5 = 7D-35
Subtract 4D from each side
-5 = 3D - 35
Add 35 to each side
30 = 3D
Divide each side by 3
D = 10
.
If the daughter is 10, the father is 40.
Five years ago, she was 5 and he was 35 (7 times her age)