Tính:
a) $\dfrac{1}{\sqrt[3]{16}+\sqrt[3]{12}+\sqrt[3]{9}}-\sqrt[3]{-3}$;
b) $\dfrac{5}{\sqrt[3]{9}-\sqrt[3]{6}+\sqrt[3]{4}}-\sqrt[3]{3}$;
c) $\dfrac{1}{\sqrt[3]{6}+\sqrt[3]{4}+\sqrt[3]{9}}+\sqrt[3]{2}$.
a)
$\frac{\sqrt[3]{4}-\sqrt[3]{3}}{(\sqrt[3]{4}-\sqrt[3]{3})(\sqrt[3]{16}+\sqrt[3]{12}+\sqrt[3]{9})}=\frac{\sqrt[3]{4}-\sqrt[3]{3}}{4-3}=\sqrt[3]{4}-\sqrt[3]{3}$
Nên biểu thức $=\sqrt[3]{4}-\sqrt[3]{3}+\sqrt[3]{3}=\sqrt[3]{4}$
Câu b:
Biểu thức = $\frac{5(\sqrt[3]{3}+\sqrt[3]{2})}{3-2}-\sqrt[3]{3}=4\sqrt[3]{3}+5\sqrt[3]{2}$
Câu c:
Biểu thức = $\frac{\sqrt[3]{3}-\sqrt[3]{2}}{3-2}+\sqrt[3]{2}=\sqrt[3]{3}$