Đáp án:
b. \(\dfrac{{\sqrt 5 }}{{\sqrt 2 }}\)
Giải thích các bước giải:
\(\begin{array}{l}
a.\dfrac{{\sqrt 6 - \sqrt 5 }}{{\sqrt {35} - \sqrt {14} }} = \dfrac{{\sqrt 6 - \sqrt 5 }}{{\sqrt 7 \left( {\sqrt 5 - \sqrt 2 } \right)}}\\
b.\dfrac{{5 + \sqrt 5 }}{{\sqrt {10} + \sqrt 2 }} = \dfrac{{\sqrt 5 \left( {\sqrt 5 + 1} \right)}}{{\sqrt 2 \left( {\sqrt 5 + 1} \right)}} = \dfrac{{\sqrt 5 }}{{\sqrt 2 }}\\
c.\sqrt 3 + \sqrt 5 .\sqrt 2 = \sqrt 3 + \sqrt {10} \\
d.\dfrac{{\sqrt {36} - 12\sqrt 5 }}{{\sqrt 6 }} = \dfrac{{\sqrt 6 \left( {\sqrt 6 - 2\sqrt {30} } \right)}}{{\sqrt 6 }}\\
= \sqrt 6 - 2\sqrt {30} \\
e.\dfrac{{\sqrt 3 - \sqrt 5 }}{{\sqrt 2 }} = \dfrac{{\left( {\sqrt 3 - \sqrt 5 } \right)\sqrt 2 }}{2}\\
= \dfrac{{\sqrt 6 - \sqrt {10} }}{2}
\end{array}\)
