\(\sqrt{8-a}+\sqrt{5+a}=5\left(Đk:-5\le a\le8\right)\)
\(8-a+5+a+2\sqrt{\left(8-a\right)\left(5+a\right)}=25\)
\(\sqrt{\left(8-a\right)\left(5+a\right)}=6\)
Cho \(x=\sqrt{6+2\sqrt{2}.\left(\sqrt{\frac{5}{2}-\sqrt{6}+\sqrt{\left(3\sqrt{a}+1\right)\left(2a-2\right)-\frac{6a^2+6\sqrt{a}-8a-4a\sqrt{a}}{\sqrt{a}-1}+8}}\right)}\) với a là số thực không âm
\(y=\frac{\frac{x-2}{x}+\frac{1}{x-2}}{12-8\sqrt{5}}.\left(-16\right)\)
So sánh x và y
Giá trị biểu thức \(\sqrt{8-a}+\sqrt{a+5}\)biết \(\sqrt{\left(8-a\right)\left(5+a\right)}=34\)
Thu gọn
a) A=\(\dfrac{2\left(\sqrt{2}+\sqrt{6}\right)}{3\sqrt{2+\sqrt{3}}}\) b)B=\(\sqrt{8-2\sqrt{15}}-\sqrt{\left(3-3\sqrt{5}\right)^2}\)
c) C=\(2\sqrt{8\sqrt{3}-2\sqrt{5\sqrt{3}}-3\sqrt{20\sqrt{3}}}\)
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) \(\left(2-\sqrt{5}\right).\sqrt{9+4\sqrt{5}}\)
cho hàm số
\(f\left(x\right)=\left(x^3+12x-31\right)^{2012}\)
tính \(f\left(a\right)\)tại \(a=\sqrt[3]{16-8\sqrt{5}}+\sqrt[3]{16+8\sqrt{5}}\)
a)\(\sqrt{\sqrt{5}-\sqrt{3x}}\)
b) \(\sqrt{\sqrt{6x}-4x}\)
c) \(\sqrt{\left(\sqrt{x}-7\right)\left(\sqrt{x}+7\right)}\)
d) \(\sqrt{\left(x-6\right)^6}\)
e) \(\sqrt{-12x+5}\)
f) \(2-4\sqrt{5x+8}\)
g) \(\sqrt{x^2-9}\)
cho x=\(\left(\dfrac{\sqrt[3]{8-3\sqrt{5}}+\sqrt[3]{64-12\sqrt{20}}}{\sqrt[3]{57}}\right)\sqrt[3]{8+3\sqrt{5}}\);y=\(\left(\dfrac{\sqrt[3]{9}-\sqrt{2}}{\sqrt[3]{3}+\sqrt[4]{2}}+\dfrac{\sqrt{2}-9\sqrt[3]{9}}{\sqrt[4]{2}-\sqrt[3]{81}}\right)\)
a rút gọn x và y
b tính T = xy
Tính: a, \(\left(4\sqrt{2}-\dfrac{11}{2}\sqrt{8}-\dfrac{1}{3}\sqrt{288}+\sqrt{50}\right)\left(\dfrac{1}{2}\sqrt{2}\right)\)
b, \(\left(\dfrac{4}{5}\sqrt{5}-\dfrac{1}{3}\sqrt{\dfrac{1}{5}}+3\sqrt{20}+\dfrac{1}{2}\sqrt{245}\right)\div\sqrt{5}\)
a, \(\sqrt{200}-\sqrt{32}+\sqrt{72}\)
b, \(4\sqrt{20}-3\sqrt{125}+5\sqrt{45}-15\sqrt{\dfrac{1}{5}}\)
c, \(\left(2\sqrt{8}+3\sqrt{5}-7\sqrt{2}\right)\left(72-5\sqrt{20}-2\sqrt{2}\right)\)
