`A = \sqrt{8} - 2\sqrt{18} + 3\sqrt{50}`
`= 2\sqrt{2} - 6\sqrt{2} + 15\sqrt{2}`
`= 11\sqrt{2}`
`B = \sqrt{125} - 10\sqrt{1/20} - (\sqrt{5}-5)/\sqrt{5}`
`= 5\sqrt{5} - \sqrt{5} - (1-\sqrt{5})`
`= 5\sqrt{5} - \sqrt{5} - 1 + \sqrt{5}`
`= 5\sqrt{5}-1`
`C = 1/(\sqrt{3}+\sqrt{2}) + \sqrt{7-4\sqrt{3}} + \sqrt{2}`
`= 1/(\sqrt{3} + \sqrt{2}) + 2 - \sqrt{3} + \sqrt{2}`
`= \sqrt{3} - \sqrt{2} + 2 - \sqrt{3} + \sqrt{2}`
`= \sqrt{3} + 2 - \sqrt{3}`
`= 2`
`D = ( 1 + 1/(cot^2 20^0) ). cos^2 20^0 - tan 40^0 . tan 50^0`
`= 1 - 1`
`= 0`
