Đáp án:
\(\begin{array}{l}
a)6\\
b)2\sqrt 6 \\
c)\dfrac{{5\sqrt 5 - 2\sqrt 2 }}{{\sqrt {10} }}\\
d)\sqrt 3 \\
e)\sqrt 2 \\
g\dfrac{{5\sqrt 3 }}{6}\\
h)3\sqrt 2 + 2\sqrt 3
\end{array}\)
Giải thích các bước giải:
\(\begin{array}{l}
a)\left( {5\sqrt 3 - 3\sqrt 3 } \right).\sqrt 3 \\
= 2\sqrt 3 .\sqrt 3 = 2.3 = 6\\
b)\left( {2\sqrt 2 - 4\sqrt 2 + 3\sqrt 2 } \right).2\sqrt 3 \\
= \sqrt 2 .2\sqrt 3 = 2\sqrt 6 \\
c)\left( {\dfrac{{\sqrt 5 }}{2} - \dfrac{{\sqrt 2 }}{5}} \right).\sqrt {10} \\
= \dfrac{{5\sqrt 5 - 2\sqrt 2 }}{{10}}.\sqrt {10} \\
= \dfrac{{5\sqrt 5 - 2\sqrt 2 }}{{\sqrt {10} }}\\
d)3\sqrt 3 - 2\sqrt 3 = \sqrt 3 \\
e)\dfrac{2}{{\sqrt 2 }} = \sqrt 2 \\
g)\dfrac{5}{{2\sqrt 3 }} = \dfrac{{5\sqrt 3 }}{6}\\
h)\dfrac{6}{{3\sqrt 2 - 2\sqrt 3 }} = \dfrac{{6\left( {3\sqrt 2 + 2\sqrt 3 } \right)}}{{18 - 12}}\\
= 3\sqrt 2 + 2\sqrt 3
\end{array}\)
