Đáp án:
C1: 2) \(\sqrt 5 + 1\)
Giải thích các bước giải:
\(\begin{array}{l}
C1:\\
1)\left( {2\sqrt 3 + 3\sqrt 3 - \sqrt 3 } \right).\dfrac{1}{{\sqrt 3 }}\\
= 4\sqrt 3 .\dfrac{1}{{\sqrt 3 }} = 4\\
2)2 + \sqrt {5 - 2\sqrt 5 .1 + 1} \\
= 2 + \sqrt {{{\left( {\sqrt 5 - 1} \right)}^2}} \\
= 2 + \sqrt 5 - 1 = \sqrt 5 + 1\\
C2:\\
1)DK:x \le 0\\
2)DK:x \ge 0\\
3)DK:2x + 1 \ge 0\\
\to x \ge - \dfrac{1}{2}\\
4)DK:3 - 6x \ge 0\\
\to \dfrac{1}{2} \ge x
\end{array}\)
