` b) ` ` \sqrt{(2 - \sqrt{3})^{2}} + \sqrt{4 - 2\sqrt{3}} `
` = 2 - \sqrt{3} + \sqrt{(\sqrt{3} - 1)^{2}} `
` = 2 - \sqrt{3} + \sqrt{3} - 1 `
` = 1 `
` c) ` ` (15\sqrt{200} - 3\sqrt{450} + 2\sqrt{50}) : \sqrt{10} `
` = \frac{150\sqrt{2} - 45\sqrt{2} + 10\sqrt{2}}{\sqrt{10}} `
` = \frac{115\sqrt{2}}{\sqrt{10}} `
` = \frac{115\sqrt{2} . \sqrt{10}}{\sqrt{10}.\sqrt{10}} `
` = \frac{115\sqrt{20}}{10} `
` = \frac{23\sqrt{20}}{2} `
` = \frac{46\sqrt{5}}{2} `
` = 23\sqrt{5} `
