Find four solutions for the following equation: x - y = 0

x –  y = 0
Take x = 1, 1 – y = 0  
                ∴ y = 1
Take x = 2, 2 – y = 0
              ∴  y = 2
Take x = 3, 3 – y = 0
               ∴ y = 3
Take  x = 4, 4  –  y = 0
               ∴ 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.