SOLUTION: Ginas mother is 5 times as old as gina. In 18 years, shell be twice as old as gina. How old are they now?

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Question 1117799: Ginas mother is 5 times as old as gina. In 18 years, shell be twice as old as gina. How old are they now?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +a+ = Gina's mother's age now
Let +b+ = Gina's age now
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(1) +a+=+5b+
(2) +a+%2B+18+=+2%2A%28+b+%2B+18+%29+
---------------------------------
Plug (1) into (2)
(2) +5b+%2B+18+=+2%2A%28+b+%2B+18+%29+
(2) +5b+%2B+18+=+2b+%2B+36+
(2) +3b+=+18+
(2) +b+=+6+
and
(1) +a+=+5b+
(1) +a+=+5%2A6+
(1) +a+=+30+
------------------------
Gina's mother is 30
Gina is 6
------------------------
check:
(2) +a+%2B+18+=+2%2A%28+b+%2B+18+%29+
(2) +30+%2B+18+=+2%2A%28+6+%2B+18+%29+
(2) +48+=+2%2A24+
(2) +48+=+48+
OK