Find four solutions for the following equation: (x-4)-y+4=0

(x-4)-y+4 = 0
    Take x = 1,
(1-4)-y+4 = 0
or-3-y+4 = 0
       or-y = -1         ∴ y = 1
   Take x = 2,
(2-4)-y+4 = 0
or -2-y+4 = 0
      or -y = -2         ∴ y = 2
   Take x = 3,
(3-4)-y+4 = 0
or-1-y+4 = 0
     or –y = -3         ∴ y = 3
   Take x = 4,
(4-4)-y+4 = 0
or 0-y+4 = 0
     or –y = -4         ∴ y = 4
∴ The four solutions of the given equation are x = 1, y = 1; x = 2, y = 2; x = 3, y = 3 and x = 4, y = 4.