`b)`
`(\sqrt{3} - \sqrt{2})^2`
`= \sqrt{3}^2 - 2\sqrt{3} . \sqrt{2} + \sqrt{2}^2`
`= 5 - 2\sqrt{6}`
`(3\sqrt{2} - 1)(3\sqrt{2} + 1)`
`= (3\sqrt{2})^2 - 1 `
`= 18 - 1`
`= 17`
`(\sqrt{6} + 2)(\sqrt{3} - \sqrt{2})`
`= \sqrt{6} . (\sqrt{3} - \sqrt{2}) + 2 . (\sqrt{3} - \sqrt{2})`
`= \sqrt{18} - \sqrt{12} + 2\sqrt{3} - 2\sqrt{2}`
`= 3\sqrt{2} - 2\sqrt{3} + 2\sqrt{3} - 2\sqrt{2}`
`= \sqrt{2}`