Let the smaller number be x , and the greater is 9 more then the smaller number, therefore greater number is x+9 . And there sum is 61, that is
x+x+9=61
2x+9 = 61
And that's the required equation .
Subtracting 9 from both sides
2x= 52
Dividing by 2 to both sides
x =26 .
So the smaller number is 26 and greater number is 26+9=35 .
Therefore the numbers are 26 and 35 .