A = \(\sqrt[3]{20+14\sqrt{2}}+\sqrt[3]{20-14\sqrt{2}}\)
=> A3 = 40 + 6A
<=> A = 4
A = \(\sqrt[3]{20+14\sqrt{2}}+\sqrt[3]{20-14\sqrt{2}}\)
=> A3 = 40 + 6A
<=> A = 4
\(\sqrt[3]{20+14\sqrt{2}}+\sqrt[3]{20-14\sqrt{2}}\)
Tính
Rút gọn biểu thức :
a) A=\(\sqrt[3]{2+\sqrt{5}}+\sqrt[3]{2-\sqrt{5}}\).
b)B=\(\sqrt[3]{20+14\sqrt{2}}+\sqrt[3]{20-14\sqrt{2}}\)
c) C=\(\sqrt[3]{9+4\sqrt{5}}+\sqrt[3]{9-4\sqrt{5}}.\)
tính \(x=\sqrt[3]{20+14\sqrt{2}}-\sqrt[3]{20+14\sqrt{2}}\)
tính \(x=\sqrt[3]{20+14\sqrt{2}}-\sqrt[3]{20+14\sqrt{2}}\)
Rút gọn
\(A=\sqrt[3]{20+14\sqrt{2}}+\sqrt[3]{20-14\sqrt{2}}\)
\(\sqrt[3]{20+14\sqrt{2}}-\sqrt[3]{20-14\sqrt{2}}+4=x+2\sqrt{x-2}\) . tìm x
Rút gọn \(\sqrt[3]{20+14\sqrt{2}}+\sqrt[3]{20-14\sqrt{2}}\)
Rút gọn :
a) \(\sqrt[3]{20+14\sqrt{2}}+\sqrt[3]{14\sqrt{2}-20}\)
b) \(\sqrt[3]{5\sqrt{2}+7}-\sqrt[3]{5\sqrt{2}-7}\)
rút gọn \(B=\sqrt[3]{20+14\sqrt{2}}+\sqrt[3]{20-14\sqrt{2}}\)