1.Căn lớn (2 căn 3 + 5)^2 + Căn lớn 37 – 20 căn3 2. Căn 2 – 2 căn 8 + Căn 72 – Căn 98

Bài 1.

`\sqrt{(2\sqrt{3}+5)^2} + \sqrt{37 – 20\sqrt{3}}`

`= |2\sqrt{3} + 5| + \sqrt{(\sqrt{25} – \sqrt{12})^2}`

`= 2\sqrt{3} + 5 + |\sqrt{25} – \sqrt{12}|`

`= 2\sqrt{3} + 5 + 5 – 2\sqrt{3}`

`= 10`

Bài 2.

`\sqrt{2} – 2\sqrt{8} + \sqrt{72} – \sqrt{98}`

`= \sqrt{2} – 4\sqrt{2} + 6\sqrt{2} – 7\sqrt{2}`

`= -4\sqrt{2}`

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