\(B=\frac{\sqrt{3-2\sqrt{2}}-\sqrt{3}}{\sqrt{5-2\sqrt{6}}+1}\)
Giúp mik vs m.n ơi
giúp mik vs
trục căn thức ở mẫu
\(\frac{1\sqrt{2}}{\sqrt{2}.\sqrt{2}}\) \(\frac{1\sqrt[]{3}}{\sqrt{3}.\sqrt{3}}\)\(\frac{2\sqrt{5}-5}{\sqrt{5}-2}\)\(\frac{6-2\sqrt{6}}{2-\sqrt{6}}\)\(\frac{5\sqrt{6}-6\sqrt{5}}{\sqrt{5}-\sqrt{6}}\)\(\frac{1}{\sqrt{5}-1}\)\(\frac{1}{4-2\sqrt{a}+a}\)\(\frac{1}{b-2\sqrt{b}+4}\)\(\frac{1}{b-3\sqrt{b}+9}\)
biến đổi bthuc trong căn thành bình phương một tổng hay một hiệu rồi từ đó phá bớt 1 lớp căn:
1, \(\sqrt{10+2\sqrt{6}-2\sqrt{10}-2\sqrt{15}}\)5
2, \(\sqrt{10-2\sqrt{6}-2\sqrt{10}+2\sqrt{15}}\)
3, \(\sqrt{6+2\sqrt{2}-2\sqrt{3}-2\sqrt{6}}\)
4, \(\sqrt{6-2\sqrt{2}+2\sqrt{3}-2\sqrt{6}}\)
5, \(\sqrt{8+\sqrt{8}+\sqrt{20}+\sqrt{40}}\)
Giúp mk vs nà m.n ơi .......!!!
Thanks m.n nhìu nà
Thực hiện các phép tính sau:
a) \(\frac{\sqrt{7}-5}{2}-\frac{6-2\sqrt{7}}{4}+\frac{6}{\sqrt{7}-2}-\frac{5}{4+\sqrt{7}}\)
b) \(\frac{1}{\sqrt{3}+\sqrt{2}-\sqrt{5}}-\frac{1}{\sqrt{3}+\sqrt{2}+\sqrt{5}}\)
c) \(\frac{1}{\sqrt{3}}+\frac{1}{3\sqrt{2}}+\frac{1}{\sqrt{3}}\sqrt{\frac{5}{12}-\frac{1}{\sqrt{6}}}\)
Giúp em với mọi người ơi! Em đang rất cần!
Giúp mik vs
Tính A
A=\(\frac{2\sqrt{3}-4}{\sqrt{3}-1}+\frac{2\sqrt{2}-1}{\sqrt{2}-1}-\frac{1+\sqrt{6}}{\sqrt{2}+3}\)
cmr các đẳng thức :
1/\(\sqrt[3]{2}+\sqrt[3]{20}-\sqrt[3]{25}=3\sqrt{\sqrt[3]{5}-\sqrt[3]{4}}\)
2/\(\frac{\sqrt[4]{5}+1}{\sqrt[4]{5}-1}=\sqrt[4]{\frac{3+2\sqrt[4]{5}}{3-2\sqrt[4]{5}}}\)
3/\(\sqrt[3]{\sqrt[3]{2}-1}=\sqrt[3]{\frac{1}{9}}-\sqrt[3]{\frac{2}{9}}+\sqrt[3]{\frac{4}{9}}\)
giúp mik vs mik cần gấp lắm
Thực hiện các phép tính sau:
a) \(\frac{2}{\sqrt{6}-2}+\frac{2}{\sqrt{6}+2}+\frac{5}{\sqrt{6}}\)
b) \(\left(\frac{\sqrt{6}-\sqrt{2}}{1-\sqrt{3}}-\frac{5}{\sqrt{5}}\right):\frac{1}{\sqrt{5}-\sqrt{2}}\)
c) \(\frac{2\sqrt{3-\sqrt{3+\sqrt{13+\sqrt{48}}}}}{\sqrt{6}-\sqrt{2}}\)
Mai em kiểm tra! Giúp em vs! em cảm ơn nhiều!!
\(\dfrac{\sqrt{5}}{\sqrt{5}+3}+\dfrac{2\sqrt{5}}{\sqrt{5}-3}-2:\dfrac{\sqrt{3}-\sqrt{2}}{\sqrt{10}+1}\)
M.N GIÚP MK RÚT GỌN VS Ạ
\(=\dfrac{5-3\sqrt{5}+10+6\sqrt{5}}{\left(\sqrt{5}-3\right)\left(\sqrt{5}+3\right)}-\dfrac{2\sqrt{10}+2}{\sqrt{3}-\sqrt{2}}\\ =\dfrac{15+3\sqrt{5}}{5-9}-\left(2\sqrt{10}+2\right)\left(\sqrt{3}+\sqrt{2}\right)\\ =-2\sqrt{30}-4\sqrt{5}-2\sqrt{3}-2\sqrt{2}-\dfrac{15+3\sqrt{5}}{4}\\ =\dfrac{-8\sqrt{30}-16\sqrt{5}-8\sqrt{3}-8\sqrt{2}-15-3\sqrt{5}}{4}\\ =\dfrac{-8\sqrt{30}-19\sqrt{5}-8\sqrt{3}-8\sqrt{2}-15}{4}\)
m.n giúp mk vs ak
mk xin cảm ơn ak
a.10x-9y =1
15x +21y=36
b.\(\frac{1}{\sqrt{5}-\sqrt{3}}-\frac{1}{\sqrt{5}+\sqrt{3}}\)
c.2\(\sqrt{27}-\sqrt{\frac{16}{3}}-\sqrt{48}-\sqrt{8\frac{1}{3}}\)
d.(\(\sqrt{5}+\sqrt{2}\))(\(3\sqrt{2}-1\))
Giúp mik vs ak!! Mik cảm ơn.
Rút gọn biểu thức:
a. \(\frac{6}{\sqrt{2}-\sqrt{3}+3}\)
b. \(\left(\frac{4}{\sqrt{5}+1}-\frac{4}{\sqrt{5}-1}\right):\sqrt{3+2\sqrt{2}}\)
a) Ta có: \(\frac{6}{\sqrt{2}-\sqrt{3}+3}\)
\(=\frac{6\left(\sqrt{2}-\sqrt{3}-3\right)}{\left(\sqrt{2}-\sqrt{3}+3\right)\left(\sqrt{2}-\sqrt{3}-3\right)}\)
\(=\frac{6\left(\sqrt{2}-\sqrt{3}-3\right)}{5-2\sqrt{6}-9}\)
\(=\frac{6\left(\sqrt{2}-\sqrt{3}-3\right)}{-4-2\sqrt{6}}\)
\(=\frac{6\left(\sqrt{2}-\sqrt{3}-3\right)}{-2\sqrt{2}\left(\sqrt{2}-\sqrt{3}\right)}\)
\(=\frac{3\left(\sqrt{2}-\sqrt{3}-3\right)\left(\sqrt{2}+\sqrt{3}\right)}{-\sqrt{2}\left(\sqrt{2}-\sqrt{3}\right)\left(\sqrt{2}-\sqrt{3}\right)}\)
\(=\frac{3\sqrt{2}\left(\sqrt{2}+\sqrt{3}\right)\left(\sqrt{2}-\sqrt{3}-3\right)}{2}\)
b) Ta có: \(\left(\frac{4}{\sqrt{5}+1}-\frac{4}{\sqrt{5}-1}\right):\sqrt{3+2\sqrt{2}}\)
\(=\left(\frac{4\left(\sqrt{5}-1\right)}{\left(\sqrt{5}+1\right)\left(\sqrt{5}-1\right)}-\frac{4\left(\sqrt{5}+1\right)}{\left(\sqrt{5}+1\right)\left(\sqrt{5}-1\right)}\right):\sqrt{2+2\cdot\sqrt{2}\cdot1+1}\)
\(=\left(\frac{4\left(\sqrt{5}-1\right)}{4}-\frac{4\left(\sqrt{5}+1\right)}{4}\right):\sqrt{\left(\sqrt{2}+1\right)^2}\)
\(=\left(\sqrt{5}-1-\sqrt{5}-1\right):\left|\sqrt{2}+1\right|\)
\(=-\frac{2}{\sqrt{2}+1}\)(Vì \(\sqrt{2}+1>0\))
\(=-\frac{2\left(\sqrt{2}-1\right)}{\left(\sqrt{2}+1\right)\left(\sqrt{2}-1\right)}\)
\(=-2\left(\sqrt{2}-1\right)\)
\(=-2\sqrt{2}+2\)