Question 1064280
Original number, {{{100h+10t+u}}}


{{{system(h+t+u=20,100h+10t+u-(100u+10t+h)=297)}}}


{{{system(h+t+u=20,99h-99u=297)}}}


{{{system(h+t+u=20,h-u=3)}}}


Treat t as a constant.
{{{system(h+u=20-t,h-u=3)}}}
Continue with the Elimination Method.  Remember, you are looking for only DIGITS for h, t, and u.