Algebra

Jerry is presently twice as old as his brother and six years older than his sister. How many years from now will Jerry's age be  1/3 of the combined ages of his brother and sister at that time?

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$j=2b=s+6\\ j+x=\frac{1}{3}(b+x+s+x)\\ j+x=\frac{1}{3}(\frac{j}{2}+j-6+2x)\\ j+x=\frac{1}{3}\cdot \frac{j+2j-12+4x}{2}\\ 6j+6x=3j-12+4x$

$2x=-3j-12\\ -x=\frac{3}{2}j+6$

- x |  9 12 15 18   21   24   27  30   33   36

   j |  2   4   6   8   10   12   14   16   18   20 

  s |                 2     4     6     8    10  12   14

  b |                 4     5     6     7     8     9   10 

At no point was, is and will Jerry be 1/3 the age of his siblings together.

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