a: \(A^3=2+\sqrt{5}+2-\sqrt{5}+3\cdot A\cdot\sqrt[3]{4-5}\)
\(\Leftrightarrow A^3=4-3A\)
=>A=1
c: \(C=1+\sqrt[3]{9+4\sqrt{5}}+\sqrt[3]{9-4\sqrt{5}}\)
\(=1+3=4\)
Thực hiện các phép tính sau :
a)A=\(\sqrt[3]{2+\sqrt{5}}+\sqrt[3]{2-\sqrt{5}}\) b)B=\(\left(2-\sqrt{3}\right).\sqrt[3]{26+15\sqrt{3}}\) c)C=\(\sqrt[3]{3+\sqrt{9+\dfrac{125}{27}}}-\sqrt[3]{-3+\sqrt{9+\dfrac{125}{7}}}\)
Rút gọn biểu thức
\(M=\sqrt[3]{26+15\sqrt{3}}.\left(2-\sqrt{3}\right)+\sqrt[3]{9+\sqrt{80}}+\sqrt[3]{9-\sqrt{80}}\)
1.Chứng minh:\(\dfrac{a+\sqrt{2+\sqrt{5}.}\sqrt{\sqrt{9-4\sqrt{5}}}}{3\sqrt{2-\sqrt{5}}.\sqrt[3]{\sqrt{9+4\sqrt{5}-}3\sqrt{a^2}+\sqrt[3]{a}}}\)=\(-\sqrt[3]{a}-1\)
2.Rút gọn: \(\left(\dfrac{a^3\sqrt[]{a}-2a^3\sqrt{b}+\sqrt[3]{a^2}-\sqrt[3]{b}}{\sqrt[3]{a^2-\sqrt[3]{ab}}}+\dfrac{\sqrt[3]{a^2b}-\sqrt[3]{ab^2}}{\sqrt[3]{a}-\sqrt[3]{b}}\right)1\dfrac{1}{\sqrt[3]{a^2}}\)
So sánh:M=\(\sqrt[3]{7+5\sqrt{2}}\)+\(\sqrt[3]{7-5\sqrt{2}}\) và N=\(\dfrac{4}{\sqrt[3]{9}}\)
tính
a. \(\dfrac{\sqrt[3]{125}.\sqrt[3]{\dfrac{16}{10}}.\sqrt[3]{-0,5}}{\sqrt[3]{4}+\sqrt[3]{2}+1}\)
b.\(\sqrt[]{3+\sqrt[]{5}+\sqrt[]{10+6\sqrt[]{5}}}\)
Tính:a)\(\left(\dfrac{1}{2}\sqrt[3]{9}-2\sqrt[3]{3}+3\sqrt[3]{\dfrac{1}{3}}\right)\):\(2\sqrt[3]{\dfrac{1}{3}}\)
b)\(\left(\sqrt[3]{4}+1\right)^3\)-\(\left(\sqrt[3]{4}-1\right)^3\)
c)\(\left(12\sqrt[3]{2}+\sqrt[3]{16}-2\sqrt[3]{2}\right)\)\(\left(5\sqrt[3]{4}-3\sqrt[3]{\dfrac{1}{2}}\right)\)
Tính:
a)\(\sqrt[3]{125}.\sqrt[3]{\dfrac{16}{10}}.\sqrt[3]{-0,5}\)
b) \(\dfrac{\sqrt[3]{4}+\sqrt[3]{2}+2}{\sqrt[3]{4}+\sqrt[3]{2}+1}\)
c) \(\sqrt{3}+\sqrt[3]{10+6\sqrt{3}}\)
d) \(\dfrac{4+2\sqrt{3}}{\sqrt[3]{10+6\sqrt{3}}}\)
e) E=\(\sqrt[3]{2+10\sqrt{\dfrac{1}{27}}}+\sqrt[3]{2-10\sqrt{\dfrac{1}{27}}}\)
Cho x =\(\dfrac{2-\left(\sqrt{5}+2\right)\sqrt[3]{17\sqrt{5}-38}}{\sqrt{4+2\sqrt{5}}-\sqrt{3}}\)
Tính P =\(x^{11}-x^{10}+x^9-x^8+x^7-x^6+99\)
so sánh
\(M=\sqrt[3]{7+5\sqrt{2}}+\sqrt[3]{7-5\sqrt{2}}\) và\(N=\dfrac{4}{\sqrt[3]{9}}\)
