Using equations you get [tex]x + x+9=81[/tex] because one number is 9 more than the other and the sum is 81. Simplifying you get, [tex]2x = 72[/tex]. Divide both sides by 2 to get [tex]x=36[/tex]. Remember this is only x so to get the other number you have to add 9 to 36 to get 45 as the other number.
