Đáp án:
$\begin{array}{l}
2)g)2 = 1 + 1 < 1 + \sqrt 2 \\
h)1 = 2 - 1 = \sqrt 4 - 1 > \sqrt 3 - 1\\
B3)a)\sqrt 7 + \sqrt {15} < \sqrt 9 + \sqrt {16} \\
Do:\sqrt 9 + \sqrt {16} = 3 + 4 = 7\\
\Leftrightarrow \sqrt 7 + \sqrt {15} < 7\\
b)3\sqrt {26} > 3\sqrt {25} = 3.5 = 15\\
c)\sqrt 2 + \sqrt {11} < \sqrt 3 + \sqrt {25} = \sqrt 3 + 5\\
d) - 30 = - 5.6 = - 5.\sqrt {36} < - 5.\sqrt {35} \\
e)\frac{{30 - 2\sqrt {45} }}{4} = \frac{{15 - 3\sqrt 5 }}{2}\\
\sqrt {17} = \frac{{2\sqrt {17} }}{2} > \frac{{15 - 3\sqrt 5 }}{2}\\
\Leftrightarrow \frac{{30 - 2\sqrt {45} }}{4} < \sqrt {17} \\
f)\sqrt {15} + \sqrt {24} < \sqrt {16} + \sqrt {25} = 4 + 5 = 9\\
\sqrt {101} - 1 > \sqrt {100} - 1 = 10 - 1 = 9\\
\Leftrightarrow \sqrt {15} + \sqrt {24} < 9 < \sqrt {101} - 1
\end{array}$
