Question 843044
==>18tu-18ut=63;
   1800+10t+u-(1800+10u+t)=63;
   9t-9u=63;
   t-u=7  eqn(1)
 
==>t+u=11 & u+t=11;
   2*(t+u)=22;
    t+u=11  eqn(2)

adding eqn(1) & eqn(2)
   2t=18;
   Hence t=9;
   using eqn(1) then u=2

Hence Beth Day year of birth=1829
Thanks