The sum of the digits of a two digit number is 10. if the digits are reversed, the new number will be 18 more than the original number. find the number

t+u = 10
10u+t= 10t+u-54
Rearrange:
t+u=10
9t-9u=54
Simplify:

1st; t+u=10
2nd: t-u=6
Add 1st and 2nd and solve for t,as follows:
2t = 16
t = 8
Substitute in t+u=10 to solve for u:
8+u=10
u = 2
Original Number = 82