SOLUTION: A father is four times as old as his son.In three years time the son will be twenty seven years younger than his father. What is their present ages?

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Question 1088719: A father is four times as old as his son.In three years time the son will be twenty seven years younger than his father. What is their present ages?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +a+ = the father's age now
Let +b+ = the son's age now
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(1) +a+=+4b+
(2) +%28+b+%2B+3+%29+=+%28+a+%2B+3+%29+-+27+
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(2) +b+%2B+3+=+a+-+24+
(2) +a+-+b+=+27+
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Plug (1) into (2)
(2) +4b+-+b+=+27+
(2) +3b+=+27+
(2) +b+=+9+
and
(1) +a+=+4b+
(1) +a+=+4%2A9+
(1) +a+=+36+
The father is 36
The son is 9
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check:
(2) +%28+b+%2B+3+%29+=+%28+a+%2B+3+%29+-+27+
(2) +%28+9+%2B+3+%29+=+%28+36+%2B+3+%29+-+27+
(2) +12+=+39+-+27+
(2) +12+=+12+
OK