You can put this solution on YOUR website! Let 10x+y = "the two digit number"
:
The sum of the two digit number is 10.
x + y = 10
or
x = (10-y); for substitution
:
If 18 be subtracted from it, the digits in the resulting number will be equal.
10x + y - 18 = a two digit number with the same digits
:
let z be the digits of the resulting two digit number, and write it:
10z + z = 10x + y - 18
:
Substitute (10-y) for x
11z = 10(10-y) + y - 18
11z = 100 - 10y + y - 18
11z = 100 - 9y - 18
11z = -9y + 82
z = y +
:
Substitute a value for y, that gives an integer value for z;
y = 3, z = 5; is the only one
then
x = 10 - 3
x = 7
:
73 = "the number"
:
see if that works
73 - 18 = 55!!
