\(\sqrt[3]{7+\sqrt{50}}+\sqrt[3]{7-\sqrt{50}}\)
\(=\sqrt[3]{2\sqrt{2}+3.2+3\sqrt{2}+1}+\sqrt[3]{-2\sqrt{2}+3.2-3\sqrt{2}+1}\)
\(=\sqrt[3]{\left(\sqrt{2}+1\right)^3}+\sqrt[3]{\left(-\sqrt{2}+1\right)^3}\)
\(=\sqrt{2}+1-\sqrt{2}+1=2\in N\)
so sánh
\(;\sqrt{2}+1vs\sqrt[3]{7+5\sqrt{2};}\) \(-6\sqrt[3]{7}\&7\sqrt[3]{\left(-6\right)}\)\(;\sqrt[3]{4}+\sqrt[3]{7}\&\sqrt[3]{11}\)\(;\sqrt[3]{10}-2vs\sqrt[3]{2}\)
So sánh:M=\(\sqrt[3]{7+5\sqrt{2}}\)+\(\sqrt[3]{7-5\sqrt{2}}\) và N=\(\dfrac{4}{\sqrt[3]{9}}\)
\(\sqrt[3]{5\sqrt{2}+7}-\sqrt[3]{5\sqrt{2}-7}\)
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=\(\sqrt[3]{26+15\sqrt{3}}.\left(2-\sqrt{3}\right)+\sqrt[3]{9+\sqrt{80}}+\sqrt[3]{9-\sqrt{80}}\)
Tính A=\(\sqrt[3]{7+5\sqrt{2}}-\sqrt[3]{7-5\sqrt{2}}\)
tính \(\sqrt[3]{7+5\sqrt{2}}-\dfrac{1}{\sqrt[3]{7+5\sqrt{2}}}\)
so sánh
\(M=\sqrt[3]{7+5\sqrt{2}}+\sqrt[3]{7-5\sqrt{2}}\) và\(N=\dfrac{4}{\sqrt[3]{9}}\)
Cho a = \(\sqrt[3]{7+5\sqrt{2}}-\frac{1}{\sqrt[3]{7+5\sqrt{2}}}\). Hãy tính a3 +3a
giải giúp em câu này với ạ tại em đang cần gấp ạ
\(\sqrt[3]{72-32\sqrt{5}}nhân\sqrt{7+3\sqrt{5}};\)\(\sqrt[3]{2+\sqrt{5}}+\sqrt[3]{2+\sqrt{5}}\)
