[tex]a = \sqrt{2} + 1 \\ b = \sqrt{3} + 1 \\ a + b = ( \sqrt{2} + 1) + ( \sqrt{3} + 1) \\ a + b = \sqrt{2} + 1 + \sqrt{3} + 1 \\ a + b = \sqrt{2} + 2 + \sqrt{3} [/tex]
[tex]a - b = ( \sqrt{2} + 1) - ( \sqrt{3} + 1) \\ a - b = \sqrt{2} + 1 - \sqrt{3} - 1 \\ a - b = \sqrt{2} - \sqrt{3} [/tex]
