SOLUTION: A man is 3 times as old as his daughter, 8 years ago the product of their ages is 112, find their present ages

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Question 760616: A man is 3 times as old as his daughter, 8 years ago the product of their ages is 112, find their present ages
Found 2 solutions by unlockmath, tommyt3rd:
Answer by unlockmath(1688) About Me  (Show Source):
You can put this solution on YOUR website!
Hello,
Good problem.
Setting up the 2 equations correctly is the key. Let "m" represent man and "d" for daughter:
m=3d
(m-8)(d-8)=112
Substitute to get:
(3d-8)(d-8)=112
Expand out to:
3d^2-32d+64=112
Rewritten as:
3d^2-32d-48=0
Use quadratic Formula and we get:
d=12
So the father is 36 years old.
Make sense?
RJ
www.math-unlock.com

Answer by tommyt3rd(5050) About Me  (Show Source):
You can put this solution on YOUR website!
Notice:
Factors of 112 are
1, 112
2, 56
4, 28 <--- most likely ages 8 years ago!
7, 16
8, 14



Now we verify...
3(4+8)=36=28+8

so their ages are 12 and 36