Rút gọn: 1/3-2căn2 + 1/2+căn5

`1/(3 - 2\sqrt{2}) + 1/(2 + \sqrt{5})`

`= (3 + 2\sqrt{2})/((3 - 2\sqrt{2})(3 +2\sqrt{2})) + (2 -\sqrt{5})/((2 - \sqrt{5})(2 + \sqrt{5}))`

`= (3 + 2\sqrt{2})/(9 - 8) + (2 - \sqrt{5})/(4 - 5)`

`= (3 +2\sqrt{2})/1 + (2 - \sqrt{5})/(-1)`

`= 3 + 2\sqrt{2} -2 + \sqrt{5}`

`= 1 +2\sqrt{2} + \sqrt{5}`

`@`Duongg7109612009