\(x=\dfrac{3}{\sqrt[3]{4}-\sqrt[3]{2}+1}=\dfrac{3\left(\sqrt[3]{2}+1\right)}{\left(\sqrt[3]{2}+1\right)\left(\sqrt[3]{4}-\sqrt[3]{2}+1\right)}=\dfrac{3\left(\sqrt[3]{2}+1\right)}{3}=3\sqrt[3]{2}+1\)
\(y=\dfrac{6}{\sqrt[3]{16}+\sqrt[3]{4}+4}=\dfrac{6}{\sqrt[3]{4}\left(\sqrt[3]{16}+\sqrt[3]{4}+1\right)}=\dfrac{6\left(\sqrt[3]{4}-1\right)}{\sqrt[3]{4}\left(\sqrt[3]{4}-1\right)\left(\sqrt[3]{16}+\sqrt[3]{4}+1\right)}=\dfrac{6\left(\sqrt[3]{4}-1\right)}{\sqrt[3]{4}.3}=\dfrac{2\left(\sqrt[3]{4}-1\right)}{\sqrt[3]{4}}=\dfrac{2\sqrt[3]{4}}{\sqrt[3]{4}}-\dfrac{\sqrt[3]{8}}{\sqrt[3]{4}}=2-\sqrt[3]{2}\)
=> x + y = \(\sqrt[3]{2}+1+2-\sqrt[3]{2}=3\)
