Question 444503
Let x be the smaller number.
Let 10x be the larger number (as it is 10 times as large as the other number).
...
10x-x=81  ...(The difference of the two numbers is 81)
9x=81
x=81/9
x=9 ... (smaller number)
10x=90 ... (larger number)
...
Therefore, the two numbers are 9 and 90.
I hope that helps you understand these types of problems.