Question 1179313
{{{100h+10t+u}}}, the number



{{{system(h+t+u=9,2t=h+u,u=2h)}}}
You could work with this, or find other ways.


Here is a possible method.
First equation,  {{{h+u+t=9}}}
Second equation, {{{h+u=2t}}}
The substitution:  {{{2t+t=9}}}
and then
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