Question 625248
I'm 4o years old.  My daughter is 9.  How old will I be when I'm 3 times older than she is.  I'm working on a formula that looks like this: 3x=x+31.  31 being how old I was at her birth.  I'm interested in seeing how this formula is written, as well as how to solve it.
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The difference will always be 31 (30 or 32 sometimes, depending on bdays)
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3 times older = 4 times as old.
There's no integer solution for 4 times and 31.
m = mother's age
d = daughter's age
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m = d + 31
m = 4d
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4d = d + 31
3d = 31
d = 10 1/3 yrs
m = 41 1/3 yrs
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Same for 3 times, no integer solution.
31 is a prime number, so it doesn't work out.
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If the difference is, eg, 32 yrs, you can have several multiples with integers.