SOLUTION: the present age of Lewis and Brown are in the ratio 1:2. three years from now, the ages will be in the ratio 3:5. find the present ages of Lewis and Brown.

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Question 978407: the present age of Lewis and Brown are in the ratio 1:2. three years from now, the ages will be in the ratio 3:5. find the present ages of Lewis and Brown.
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
At present:
(1) +L%2FB+=+1%2F2+
In 3 years:
(2) +%28+L+%2B+3+%29+%2F+%28+B+%2B+3+%29+=+3%2F5+
-------------------------------
(1) +B+=+2L+
By substitution:
(2) +%28+L+%2B+3+%29+%2F+%28+2L+%2B+3+%29+=+3%2F5+
Multiply both sides by +5%2A%28+2L+%2B+3+%29+
(2) +5%2A%28+L+%2B+3+%29+=+3%2A%28+2L+%2B+3+%29+
(2) +5L+%2B+15+=+6L+%2B+9+
(2) +L+=+15+-+9+
(2) +L+=+6+
and, since
(1) +B+=+2L+
(1) +B+=+2%2A6+
(1) +B+=+12+
Lewis is 6 and Brown is 12
-------------------------
check:
(2) +%28+L+%2B+3+%29+%2F+%28+B+%2B+3+%29+=+3%2F5+
(2) +%28+6+%2B+3+%29+%2F+%28+12+%2B+3+%29+=+3%2F5+
(2) +9%2F15+=+3%2F5+
(2) +%28+3%2F3+%29%2A%28+3%2F5+%29+=+3%2F5+
(2) +3%2F5+=+3%2F5+
OK