第104页 - 苏科版八年级伴你学数学答案（上下册）

B

$解:原式=\frac {\sqrt{2}}{\sqrt{5}}$

$ =\frac {\sqrt{10}}5$

$解：原式=\sqrt{\frac 87}$

$ =\frac {2\sqrt{14}}7$

$解:原式=\sqrt{3²×\frac {1}{3}}$

$=\sqrt{3}$

$解：原式=\frac {\sqrt{b}}{\sqrt{2a}}$

$ =\frac {\sqrt{2ab}}{2a}$

$解:原式=\frac {\sqrt{7}×\sqrt{2}}{\sqrt{2}×\sqrt{2}}$

$ =\frac {\sqrt{14}}2$

$解:原式=\frac {2}{3\sqrt{2}}$

$=\frac {\sqrt{2}}{3}$

$解：原式=\frac {3×\sqrt{6x}}{\sqrt{6x}×\sqrt{6x}}$

$ =\frac {\sqrt{6x}}{2x}$

$解：原式=\frac {2×\sqrt{2b}}{a×\sqrt{2b}×\sqrt{2b}}$

$ =\frac {\sqrt{2b}}{ab}$

D

$解:原式=\sqrt{\frac {4}{3}}$

$=\frac {2\sqrt{3}}{3}$

$解:原式=9×\frac {\sqrt{2}}{\sqrt{3}}$

$=3\sqrt{6}$