\(\sqrt{19+\sqrt{136}}-\sqrt{19-\sqrt{136}}=\sqrt{17+2\sqrt{17.2}+2}-\sqrt{17-2\sqrt{17.2}+2}\)
\(=\sqrt{\left(\sqrt{17}+\sqrt{2}\right)^2}-\sqrt{\left(\sqrt{17}-\sqrt{2}\right)^2}=\sqrt{17}+\sqrt{2}-\sqrt{17}+\sqrt{2}\)
\(=2\sqrt{2}\)
\(\sqrt{5+\sqrt{19+2\sqrt{5}}}\) - \(\sqrt{5-\sqrt{19+2\sqrt{5}}}\)
rút gọn
A=\(\frac{1}{1+\sqrt{2}}+\frac{1}{\sqrt{2}+\sqrt{3}}+........+\frac{1}{\sqrt{19}+\sqrt{20}}\)
B=\(\frac{1}{2\sqrt{1}+1\sqrt{2}}+\frac{1}{3\sqrt{2}+2\sqrt{3}}+......+\frac{1}{20\sqrt{19}+19\sqrt{20}}\)
40.A=\(\dfrac{2-5\sqrt{x}}{\sqrt{x}+1}\)
a. Tính giá trị của biểu thức A khi x=\(\sqrt{19+8\sqrt{3}}+\sqrt{19-8\sqrt{3}}\)
\(\sqrt{13-4\sqrt{3}}+\sqrt{13+4\sqrt{3}}\)
\(\sqrt{19-6\sqrt{2}}-\sqrt{19+6\sqrt{2}}\)
có ai biết giải bài này k hộ mình vs ( giải chi tiết hộ mình nhé)
1, \(\left(\sqrt{19}-3\right)\left(\sqrt{19}+3\right)\)
2, \(\sqrt{4+\sqrt{7}}-\sqrt{4-\sqrt{7}}\)
3, \(\sqrt{8+\sqrt{60}}+\sqrt{45}-\sqrt{12}\)
4, \(\sqrt{9-4\sqrt{5}}-\sqrt{9+4\sqrt{5}}\)
1. Tính ( rút gọn)
a)\(\sqrt{\left(5-\sqrt{19}\right)^2}-\sqrt{\left(4-\sqrt{19}\right)^2}\)
b)\(\sqrt{\left(3-2\sqrt{2}\right)^2}-\sqrt{\left(2\sqrt{2}-3\right)^2}\)
c)\(\sqrt{8+2\sqrt{15}}+\sqrt{\left(\sqrt{2-\sqrt{5}}\right)^2}\)
d)\(\sqrt{12+6\sqrt{3}}.\left(3+\sqrt{3}\right)\)
e) \(\left(2-\sqrt{5}\right).\sqrt{9+4\sqrt{5}}\)
Giải phương trình :
\(\sqrt{136-x^2}+\sqrt{106-x^2}=\frac{60}{x}\)
cac ban giai giup mk bai nay nha
\(\sqrt{19+8\sqrt{3}}-\sqrt{19-8\sqrt{3}}=?\)
\(\sqrt{x+2\sqrt{x-1}}+\sqrt{x-2\sqrt{x-1}}=?\)
Tình
A= \(\dfrac{\sqrt{9+\sqrt{5}}+\sqrt{9-\sqrt{5}}}{\sqrt{9+ 2\sqrt{19}}}-\sqrt{3-2\sqrt{2}}\)
