\(a.4\sqrt{2}+5\sqrt{2}-20\sqrt{2}+18\sqrt{2}=7\sqrt{2}\)
\(a,=4\sqrt{2}+5\sqrt{2}-20\sqrt{2}+18\sqrt{2}=7\sqrt{2}\\ b,=\dfrac{3\left(\sqrt{2}+1\right)}{1}+\left|3-\sqrt{2}\right|-2\sqrt{2}\\ =3\sqrt{2}+3+3-\sqrt{2}-2\sqrt{2}=6\)
`a)`
`\sqrt{32} + \sqrt{50} - 2\sqrt{200} + 3\sqrt{72}`
`= 4\sqrt{2} + 5\sqrt{2} - 20\sqrt{2} + 18\sqrt{2}`
`= (4 + 5 - 20 + 18) . \sqrt{2}`
`= 7\sqrt{2}`
`b)`
`3/(\sqrt{2} - 1) + \sqrt{(3 - \sqrt{2})^2} - 2\sqrt{2}`
`= (3 . (\sqrt{2} + 1))/1 + |3 - \sqrt{2}| - 2\sqrt{2}`
`= 3\sqrt{2} + 3 + 3 - \sqrt{2} - 2\sqrt{2}`
`= (3 - 1 - 2) . \sqrt{2} + 6`
`= 6`