`1)` `A=\sqrt{3-2\sqrt{2}}+\sqrt{4-2\sqrt{3}}-\sqrt{5-2\sqrt{6}}`
`=\sqrt{2-2\sqrt{2}+1}+\sqrt{3-2\sqrt{3}+1}-\sqrt{3-2\sqrt{3.2}+2}`
`=\sqrt{(\sqrt{2}-1)^2}+\sqrt{(\sqrt{3}-1)^2}-\sqrt{(\sqrt{3}-\sqrt{2})^2}`
`=|\sqrt{2}-1|+|\sqrt{3}-1|-|\sqrt{3}-\sqrt{2}|`
`=\sqrt{2}-1+\sqrt{3}-1-(\sqrt{3}-\sqrt{2})`
`=\sqrt{2}+\sqrt{3}-2-\sqrt{3}+\sqrt{2}`
`=2\sqrt{2}-2`
`2)` `B=\sqrt{8}-\sqrt{1/9}+\sqrt{20}.\sqrt{45}`
`=\sqrt{4.2}-frac{\sqrt{1}}{\sqrt{9}}+\sqrt{4.5}.\sqrt{9.5}`
`=2\sqrt{2}-frac{1}{3}+2\sqrt{5}.3\sqrt{5}`
`=2\sqrt{2}-1/3+30`
`=2\sqrt{2}+(89)/(3)`
`=frac{89+6\sqrt{2}}{3}`
`3)` `C=\sqrt{(3-\sqrt{7})^2}+\sqrt{8+2\sqrt{7}}`
`=|3-\sqrt{7}|+\sqrt{7+2\sqrt{7.1}+1}`
`=3-\sqrt{7}+\sqrt{(\sqrt{7}+1)^2}`
`=3-\sqrt{7}+|\sqrt{7}+1|`
`=3-\sqrt{7}+\sqrt{7}+1`
`=4`
