Question 1197732
Number,  {{{10t+u}}}


{{{system(t+u=6,10u+t=18+10t+u)}}}


{{{system(t+u=6,9u-9t=18)}}}


{{{system(t+u=6,u-t=2)}}}


{{{system(u+t=6,u-t=2)}}}
May be able to see without making steps on paper,
u=4 and t=2;


The two-digit number,  24.