Question 821025
The ages of moe and joe now total 49 years. 
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M+J = 49
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Moe's age now is twice the age that joe was...
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Stop here. Let y = the number of years ago that was.

y years ago, Moe was M-y and Joe was J-y

M = 2(J-y)

Now let's see what else was true y years ago:   
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...when moe's age was the same as joe's is now.
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M-y = J

So we have these three equations:

M+J = 49 
M = 2*(J-y)
M-y = J

Solve that system of equations and get J=21, M=28, y=7

Edwin</pre>