Sửa đề: \(\sqrt{10-2\sqrt{21}}-\sqrt{34+2\sqrt{189}}\)
\(=\sqrt{7}-\sqrt{3}-3\sqrt{3}-\sqrt{7}=-4\sqrt{3}\)
Sửa đề: \(\sqrt{10-2\sqrt{21}}-\sqrt{34+2\sqrt{189}}\)
\(=\sqrt{7}-\sqrt{3}-3\sqrt{3}-\sqrt{7}=-4\sqrt{3}\)
Rút gọn:
a) \(\sqrt{14-6\sqrt{5}}\) +\(\sqrt{6+2\sqrt{5}}\)
b) \(\dfrac{\sqrt{10}+10}{1+\sqrt{10}}-\dfrac{5\sqrt{2}-2\sqrt{5}}{\sqrt{5}-\sqrt{2}}\)
rút gọn :
a ) \(\sqrt{2}.\sqrt{7-3\sqrt{5}}\)
b) \(\sqrt{\dfrac{59}{25}+\dfrac{6}{5}\sqrt{2}}\)
c) \(2.\left(\sqrt{10}-\sqrt{2}\right).\sqrt{4+\sqrt{6-2\sqrt{5}}}\)
d) \(\left(7+\sqrt{14}\right).\sqrt{9-2\sqrt{14}}\)
Rút gọn biểu thức
\(\sqrt{14-4\sqrt{10}}-3\sqrt{14+4\sqrt{10}}\)
Rút gọn:
a) \(A=\sqrt{4+2\sqrt{2}}\sqrt{2+2+\sqrt{2}}.\sqrt{2-2+\sqrt{2}}\)
b) \(B=\left(\sqrt{2}-\sqrt{3+\sqrt{5}}\right)\sqrt{2}+2\sqrt{5}\)
c) \(C=\left(\sqrt{14}-\sqrt{10}\right)\left(\sqrt{6}+\sqrt{35}\right)\)
d) \(D=\sqrt{11-4\sqrt{7}}-\sqrt{2}.\sqrt{8+3\sqrt{7}}\)
tinh
\(\left(\sqrt{\sqrt{14}+\sqrt{5}}+\sqrt{\sqrt{14}-\sqrt{5}}\right)^2\)
tính giá trị biểu thức :
a, \(\left(\sqrt{28}+2\sqrt{14}+\sqrt{7}\right)\sqrt{7}-\left(7+\sqrt{2}\right)^2\)
b, \(\sqrt{\dfrac{5}{2}}+\dfrac{\sqrt{2}}{\sqrt{3}+\sqrt{5}}\)
c, \(\dfrac{8+2\sqrt{15}}{\sqrt{5}+\sqrt{3}}+\dfrac{7-2\sqrt{10}}{\sqrt{5}-\sqrt{2}}\)
d,\(\dfrac{3+4\sqrt{3}}{\sqrt{6}+\sqrt{2}-\sqrt{5}}\)
Đề bài: Thực hiện phép tính :
a) \(\left(\frac{2\sqrt{3}-\sqrt{6}}{\sqrt{8}-2}-\frac{\sqrt{216}}{3}\right).\frac{1}{\sqrt{6}}\)
b) \(\left(\frac{\sqrt{14}-\sqrt{7}}{1-\sqrt{2}}-\frac{\sqrt{15}-\sqrt{5}}{1-\sqrt{3}}\right):\frac{1}{\sqrt{7}+\sqrt{5}}\)
c) \(\frac{\sqrt{5+2\sqrt{6}}+\sqrt{8-2\sqrt{15}}}{\sqrt{7+2\sqrt{10}}}\)
Giúp em với ạ, em cảm ơn !
rút gọn biểu thức (3\(\sqrt{2}\)-\(\sqrt{8}+\sqrt{14}\))\(\sqrt{2}-\sqrt{7}\)
\(\left(\dfrac{\sqrt{14}-\sqrt{7}}{1-\sqrt{2}}+\dfrac{\sqrt{15}-\sqrt{5}}{1-\sqrt{3}}\right)\):\(\dfrac{1}{\sqrt{7}-\sqrt{5}}\)