Question 1100738
If you use h for hundreds digit, t for tens digit and u for units digit, then the description literally gives this system of equations:

{{{system(h+t+u=17,t=u+2h-12,h+10t+100u=100h+10t+u-297)}}}


You should be able to simplify and solve the system and get whole number results for h, t, and u.


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Simplified System:  {{{system(h+t+u=17,t=u+2h-12,h-u=3)}}}


Substitute for t:
{{{system(3h+2u=29,h-u=3)}}}


Using Elimination Method,
{{{system(h=7,u=4,and_then,t=6)}}}


The three-digit number:  764