Question

The sum of the digits of a 2-digit number is 9. On reversing its digts, the new number obtained is 45 more than the original number. Find the number.

Answer 1

27,2+7=9.reversing we get 72.72,7+2 =9. 27+45=72.

Answer 2

Let the no. be x and y

Unit's digit =x
10s digit =10y

So the original no. formed 10y+x

x+y =9
10x+y = 10y+x +45
10x-x+y-10y = 45
9x-9y = 45
x-y = 5

Putting elimination method
x+y =9
x-y =5
-  +  -
=  2y = 14
 y = 7
x+y =9
x=9-7 =2

So the original no.
10y+x = 10*7+2 =72