Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(\frac{2}{3}\sqrt{3}-\frac{1}{4}\sqrt{18}+\frac{2}{5}\sqrt{2}-\frac{1}{4}\sqrt{12}\)
\(=\frac{2}{3}\sqrt{3}-\frac{1}{4}\sqrt{3^2\cdot2}+\frac{2}{5}\sqrt{2}-\frac{1}{4}\sqrt{2^2\cdot3}\)
\(=\frac{2}{3}\sqrt{3}-\frac{3}{4}\sqrt{2}+\frac{2}{5}\sqrt{2}-\frac{1}{2}\sqrt{3}\)
\(=\frac{1}{6}\sqrt{3}-\frac{7}{20}\sqrt{2}\)
\(\frac{5\sqrt{7}-7\sqrt{5}+2\sqrt{70}}{\sqrt{35}}\)
\(=\frac{\sqrt{35}.(5\sqrt{7}-7\sqrt{5}+2\sqrt{70})}{\sqrt{35}.\sqrt{35}}\)
\(=\frac{\sqrt{35}.(5\sqrt{7}-7\sqrt{5}+2\sqrt{70})}{35}\)
\(\sqrt{\frac{4}{3}}+\sqrt{12}-\frac{4}{3}\sqrt{\frac{3}{4}}\)
\(=\frac{\sqrt{4}}{\sqrt{3}}+\sqrt{12}-\frac{4}{3}\cdot\frac{\sqrt{3}}{\sqrt{4}}\)
\(=\frac{2\sqrt{3}}{\sqrt{3}.\sqrt{3}}+\sqrt{12}-\frac{4}{3}\cdot\frac{\sqrt{3}}{2}\)
\(=\frac{2\sqrt{3}}{3}+2\sqrt{3}-\frac{2\sqrt{3}}{3}\)
\(=2\sqrt{3}\left(\frac{1}{3}+1-\frac{1}{3}\right)\)
\(=2\sqrt{3}\)
a) \(\frac{2}{3}\sqrt{3}-\frac{1}{4}\sqrt{18}+\frac{2}{5}\sqrt{2}-\frac{1}{4}\sqrt{12}\)
\(=\frac{2}{3}\sqrt{3}-\frac{1}{4}\sqrt{2\times3^2}+\frac{2}{5}\sqrt{2}-\frac{1}{4}\sqrt{3\times2^2}\)
\(=\frac{2}{3}\sqrt{3}-\frac{3}{4}\sqrt{2}+\frac{2}{5}\sqrt{2}-\frac{1}{2}\sqrt{3}\)
\(=\frac{1}{6}\sqrt{3}-\frac{7}{20}\sqrt{2}=\frac{10\sqrt{3}-21\sqrt{2}}{60}\)
b) \(\left(\sqrt{10}+\sqrt{2}\right)\left(6-2\sqrt{5}\right)\sqrt{3+\sqrt{5}}\)
\(=\sqrt{2}\left(\sqrt{5}+1\right)\left(5-2\sqrt{5}\times1+1\right)\sqrt{3+\sqrt{5}}\)
\(=\left(\sqrt{5}+1\right)\left(\sqrt{5}-1\right)^2\sqrt{6+2\sqrt{5}}\)
\(=4\left(\sqrt{5}-1\right)\sqrt{5+2\sqrt{5}\times1+1}\)
\(=4\left(\sqrt{5}-1\right)\sqrt{\left(\sqrt{5}+1\right)^2}=4\left(\sqrt{5}-1\right)\left(\sqrt{5}+1\right)\)
\(=4^2=16\)
22) \(\frac{1}{\sqrt{5}+\sqrt{2}}+\frac{1}{\sqrt{5}-\sqrt{2}}\)
\(=\frac{\left(\sqrt{5}-\sqrt{2}\right)+\left(\sqrt{5}+\sqrt{2}\right)}{\left(\sqrt{5}+\sqrt{2}\right)\left(\sqrt{5}-\sqrt{2}\right)}\)
\(=\frac{2\sqrt{5}}{\sqrt{5^2}-\sqrt{2^2}}\)
\(=\frac{2\sqrt{5}}{5-2}=\frac{2\sqrt{5}}{3}\)
Phần d mình sửa lại đề nha : \(\frac{\left(\sqrt{5}+2\right)^2-8\sqrt{5}}{2\sqrt{4}-4}\)
những ai thích xem minecraft và blockman go thì hãy xem kênh youtube của mik kênh mik là M.ichibi các bn nhớ sud và chia sẻ cho nhiều người khác nhé
\(\frac{2}{3}\sqrt{3}\)- \(\frac{1}{4}\sqrt{18}\)+ \(\frac{2}{5}\sqrt{2}-\frac{1}{4}\sqrt{12}\)
= \(\frac{2}{3}\sqrt{3}-\frac{3}{4}\sqrt{2}+\frac{2}{5}\sqrt{2}-\frac{2}{4}\sqrt{3}\)
= \(\sqrt{3}\left(\frac{2}{3}-\frac{1}{2}\right)\)- \(\sqrt{2}\left(\frac{3}{4}-\frac{2}{5}\right)\)
= \(\frac{\sqrt{3}}{6}\)- \(\frac{7}{20}\sqrt{2}\)
kq ra hơi kì
#mã mã#