document.write( "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. Thanks. \n" ); document.write( "

Algebra.Com's Answer #393394 by Alan3354(69443) $\"\"$ $\"About$

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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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\n" ); document.write( "The difference will always be 31 (30 or 32 sometimes, depending on bdays)
\n" ); document.write( "------
\n" ); document.write( "3 times older = 4 times as old.
\n" ); document.write( "There's no integer solution for 4 times and 31.
\n" ); document.write( "m = mother's age
\n" ); document.write( "d = daughter's age
\n" ); document.write( "----
\n" ); document.write( "m = d + 31
\n" ); document.write( "m = 4d
\n" ); document.write( "---
\n" ); document.write( "4d = d + 31
\n" ); document.write( "3d = 31
\n" ); document.write( "d = 10 1/3 yrs
\n" ); document.write( "m = 41 1/3 yrs
\n" ); document.write( "-------
\n" ); document.write( "Same for 3 times, no integer solution.
\n" ); document.write( "31 is a prime number, so it doesn't work out.
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\n" ); document.write( "If the difference is, eg, 32 yrs, you can have several multiples with integers. \n" ); document.write( "

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