2025年学习与评价八年级数学下册江苏凤凰教育出版社第121页答案
1. 计算:
 (1)$(\sqrt{6}-\sqrt{\frac{3}{8}})\times\sqrt{2}$;         (2)$(2+\sqrt{2})(1-\sqrt{2})$;
 (3)$(\sqrt{2}+1)(\sqrt{2}-1)$;        (4)$(\sqrt{2}-\sqrt{3})^{2}$.

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2. 计算:
 (1)$a\sqrt{16a}+3\sqrt{a^{3}}-\frac{1}{2}a\sqrt{\frac{4}{a}}(a>0)$; (2)$(2+\sqrt{5})(3 - 2\sqrt{5})$;
 (3)$(3\sqrt{2}+\sqrt{7})(3\sqrt{2}-\sqrt{7})$;       (4)$(\sqrt{5}-\sqrt{10})^{2}$.

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3. 计算:
 (1)$(\frac{-1+\sqrt{3}}{2})^{2}$;            (2)$(\frac{-1-\sqrt{5}}{2})^{2}$.

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4. 已知菱形的两条对角线长分别为$(4+\sqrt{3})\text{ cm}$、$(4-\sqrt{3})\text{ cm}$,求该菱形的面积.

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5. 已知$x=\sqrt{3}+1$,$y=\sqrt{3}-1$,求下列各式的值:
 (1)$x^{2}+2xy + y^{2}$;           (2)$x^{2}-y^{2}$.

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