a) \(\sqrt[3]{7+5\sqrt{2}}=\sqrt{2}+1\)
b) \(-6\sqrt[3]{7}=\sqrt[3]{\left(-6\right)^3\cdot7}=\sqrt[3]{-1512}\)
\(7\sqrt[3]{-6}=\sqrt[3]{7^3\cdot\left(-6\right)}=\sqrt[3]{-2058}\)
mà -1512>-2058
nên \(-6\sqrt[3]{7}>7\cdot\sqrt[3]{-6}\)
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=\(\dfrac{4}{\sqrt[3]{9}}\)
Tính
a.A=\(\sqrt[3]{2+\sqrt{5}}+\sqrt[3]{2-\sqrt{5}}\)
b.B=\(\sqrt[3]{3+\sqrt{9+\dfrac{125}{7}}}-\sqrt[3]{-3+\sqrt{9+\dfrac{125}{7}}}\)
c.C=\(\sqrt[3]{26+15\sqrt{3}}.\left(2-\sqrt{3}\right)+\sqrt[3]{9+\sqrt{80}}+\sqrt[3]{9-\sqrt{80}}\)
Thực hiện các phép tính sau:
a)\(\sqrt[3]{\left(4-2\sqrt[3]{3}\right)\left(\sqrt[3]{3}-1\right)}\)
b)\(\sqrt{3+\sqrt{3}+\sqrt[3]{10+6\sqrt{3}}}\)
cho x =\(\dfrac{7-4\sqrt{3}}{\sqrt[3]{26-15\sqrt{3}}}-\sqrt[3]{26+15\sqrt{3}}\)
tính A= \(\dfrac{x^6+x^4+4x^2}{40\left(x^4+4x^2-144\right)}\)
Thực hiện phép tính
a)\(\dfrac{\sqrt[3]{135}}{\sqrt[3]{5}}-\sqrt[3]{54}.\sqrt[3]{4}\)
b)\(\left(\sqrt[3]{25}-\sqrt[3]{10}+\sqrt[3]{4}\right)\)\(\left(\sqrt[3]{5}+\sqrt[3]{2}\right)\)
Tính:
a) \(\sqrt[3]{\left(\sqrt{2}+1\right)\left(3+2\sqrt{2}\right)}\)
b) \(\sqrt[3]{\left(4-2\sqrt{3}\right)\left(\sqrt{3}-1\right)}\)
c) \(\left(\sqrt[3]{4}+1\right)^3-\left(\sqrt[3]{4}-1\right)^3\)
d) \(\left(\sqrt[3]{9}-\sqrt[3]{6}+\sqrt[3]{4}\right)\left(\sqrt[3]{3}+\sqrt[3]{2}\right)\)
e) \(\sqrt[3]{20+14\sqrt{2}}+\sqrt[3]{20-14\sqrt{2}}\)
Mọi người giúp em với ạ!!!!!!!!!!!
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=\(\sqrt[3]{3+\sqrt{9+\dfrac{125}{27}}}-\sqrt[3]{-3+\sqrt{9+\dfrac{125}{7}}}\)
so sánh
\(M=\sqrt[3]{7+5\sqrt{2}}+\sqrt[3]{7-5\sqrt{2}}\) và\(N=\dfrac{4}{\sqrt[3]{9}}\)
