Đáp án: $\begin{array}{l}A = 27 + 2\sqrt 3 + \sqrt {48} \\ = 27 + 2\sqrt 3 + \sqrt {16.3} \\ = 27 + 2\sqrt 3 + 4\sqrt 3 \\ = 27 + 6\sqrt 3 \\B = 4\sqrt 2 – 3\sqrt 8 – \sqrt {50} \\ = 4\sqrt 2 – 3.\sqrt {4.2} – \sqrt {25.2} \\ = 4\sqrt 2 – 3.2\sqrt 2 – 5\sqrt 2 \\ = 4\sqrt 2 – 6\sqrt 2 – 5\sqrt 2 \\ = – 7\sqrt 2 \\C = \frac{1}{2}.\sqrt {12} – \sqrt {48} + 5\sqrt 3 \\ = \frac{1}{2}.\sqrt {4.3} – \sqrt {16.3} + 5\sqrt 3 \\ = \frac{1}{2}.2\sqrt 3 – 4\sqrt 3 + 5\sqrt 3 \\ = \sqrt 3 – 4\sqrt 3 + 5\sqrt 3 \\ = 2\sqrt 3 \\D = \sqrt {24} – 3\sqrt 6 + \sqrt {54} \\ = \sqrt {4.6} – 3\sqrt 6 + \sqrt {9.6} \\ = 2\sqrt 6 – 3\sqrt 6 + 3\sqrt 6 \\ = 2\sqrt 6 \end{array}$ Reply
Đáp án:
$\begin{array}{l}
A = 27 + 2\sqrt 3 + \sqrt {48} \\
= 27 + 2\sqrt 3 + \sqrt {16.3} \\
= 27 + 2\sqrt 3 + 4\sqrt 3 \\
= 27 + 6\sqrt 3 \\
B = 4\sqrt 2 – 3\sqrt 8 – \sqrt {50} \\
= 4\sqrt 2 – 3.\sqrt {4.2} – \sqrt {25.2} \\
= 4\sqrt 2 – 3.2\sqrt 2 – 5\sqrt 2 \\
= 4\sqrt 2 – 6\sqrt 2 – 5\sqrt 2 \\
= – 7\sqrt 2 \\
C = \frac{1}{2}.\sqrt {12} – \sqrt {48} + 5\sqrt 3 \\
= \frac{1}{2}.\sqrt {4.3} – \sqrt {16.3} + 5\sqrt 3 \\
= \frac{1}{2}.2\sqrt 3 – 4\sqrt 3 + 5\sqrt 3 \\
= \sqrt 3 – 4\sqrt 3 + 5\sqrt 3 \\
= 2\sqrt 3 \\
D = \sqrt {24} – 3\sqrt 6 + \sqrt {54} \\
= \sqrt {4.6} – 3\sqrt 6 + \sqrt {9.6} \\
= 2\sqrt 6 – 3\sqrt 6 + 3\sqrt 6 \\
= 2\sqrt 6
\end{array}$