Question 341243
Let x= tens digit
Let y = ones digit


Equation 1: x+y = 9
Equation 2: y=x+1


Substitute Equation 2 into Equation 1:


x+ (x+1) = 9
2x + 1 = 9
2x = 8
x = 4


So the tens digit is 4. This means that the ones digit is y =4+1 = 5


The number is 45.