Câu hỏi của Nguyễn Phạm Hùng Anh

Question

$\dfrac{1}{2}\sqrt{108}-10\sqrt{\dfrac{1}{5}}-\sqrt{147}+\sqrt{20}$

Nguyễn Ngô Minh Trí · Accepted Answer

$\dfrac{1}{2}.\sqrt{108}-10.\sqrt{\dfrac{1}{5}}-\sqrt{147}+\sqrt{20}$

$=\dfrac{1}{2}.\sqrt{6^2.3}-10.\dfrac{\sqrt{5}}{5}-\sqrt{7^2.3}+\sqrt{2^2.5}$

$=3\sqrt{3}-2\sqrt{5}+2\sqrt{5}-7\sqrt{3}$

$=-4\sqrt{3}$Câu trả lời: $\dfrac{1}{2}.\sqrt{108}-10.\sqrt{\dfrac{1}{5}}-\sqrt{147}+\sqrt{20}$

$=\dfrac{1}{2}.\sqrt{6^2.3}-10.\dfrac{\sqrt{5}}{5}-\sqrt{7^2.3}+\sqrt{2^2.5}$

$=3\sqrt{3}-2\sqrt{5}+2\sqrt{5}-7\sqrt{3}$

$=-4\sqrt{3}$