you can figure this out by setting up an equation and make
x= tens digit
y= ones digit
y + 8 =x (tens digit 8 more than ones)
also we know that
y>0
x>0
since the 10s digit and 1s digit cannot be more than one number, we can say
0 < y > 10
0 < x > 10
since x has to be greater than 0 but less than 10, there is only one number that would fit into the equation for y
2 + 8 = 10
(y cannot equal 2 because than x is equal to 10 and it must be less than)
1 + 8 = 9
( y can be 1 since x is less than 10)
so it would be
y= 1
x= 9
the number would be 91
hope this helped!
