“微信扫一扫”进入题库练习及模拟考试
计算：
\((\frac{{\sqrt {40} }}{4} - \sqrt {50} ) + 2(\sqrt {\frac{2}{5}} - \sqrt {\frac{1}{8}} )\)．
参考答案：\(\frac{{9\sqrt {10} }}{{10}} - \frac{{11\sqrt 2 }}{2}\)
进入考试题库
