mọi người giúp mình với ạ

Đáp án:

Giải thích các bước giải:

`a, A = \sqrt{(\sqrt{2 - \sqrt{3}})(\sqrt{3} + 1)`

`=> A = \sqrt{4 - 2\sqrt{3} (\sqrt{3} + 1)`

`=> A = \sqrt{3 - 2\sqrt{3} + 1} . (\sqrt{3} + 1)`

`=> A=  (\sqrt{(\sqrt{3} - 1)^2} . (\sqrt{3} + 1)`

`=> A = |\sqrt{3} - 1| . (\sqrt{3} + 1)`

`=> A=  (\sqrt{3} - 1)(\sqrt{3} + 1)`

`=> A = 3 - 1`

`=> A = 2`

Vậy `A = 2`

`b, B = \sqrt{2-\sqrt{3}} (\sqrt{6} - \sqrt{2})(2 + \sqrt{3})`

`=> B = \sqrt{2 - \sqrt{3}} . \sqrt{2} (\sqrt{3} - 1)(2 + \sqrt{3})`

`=> B = \sqrt{4 - 2\sqrt{3}} (\sqrt{3} - 1)(2 +\sqrt{3})`

`=> B = \sqrt{3 - 2\sqrt{3} + 1} (\sqrt{3} - 1)(2+ \sqrt{3})`

`=> B = \sqrt{(\sqrt{3} - 1)^2} (\sqrt{3} - 1)(2 +\sqrt{3})`

`=> B = |\sqrt{3} - 1| (\sqrt{3} - 1)(2 +\sqrt{3})`

`=> B = (\sqrt{3} - 1)^2 (2 + \sqrt{3})`

`=> B = (3 - 2\sqrt{3} + 1)(2 +\sqrt{3})`

`=> B = (4 - 2\sqrt{3})(2 +\sqrt{3})`

`=> B = 2(2 - \sqrt{3})(2 + \sqrt{3})`

`=> B = 2(4 - 3)`

`=> B = 2`

Vậy `B = 2`

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