Let 'x' be the digit at unit and 'y' be the digit at 10th. 

So the number be =x+10y 

according to condition we know 

x+y=13 i 

according to the second condition 

10x+y=(x+10y)+45 

10x+y=x+10y+45 

9x-9y=45 

x-y=5 ii 

Now to subtracting eq ii from eq i 

x+y=13 

- x-y=5 

2y=8 

y=4 

Putting the value of y in eq i 

x+y=13 

x+4=13 

x =13-4 

x =9 

Now putting the value of x and y to get the required number 

Req Number = x+10y 

=9 +10(4) 

=9+40 

=49 Answer