\(\begin{array}{l}\text { Ta có }\left(x^{2}+\frac{1}{x}\right)^{4}=C_{4}^{0}\left(x^{2}\right)^{4}+C_{4}^{1}\left(x^{2}\right)^{3} \cdot\left(\frac{1}{x}\right)+C_{4}^{2}\left(x^{2}\right)^{2} \cdot\left(\frac{1}{x}\right)^{2}+C_{4}^{3}\left(x^{2}\right) \cdot\left(\frac{1}{x}\right)^{3}+C_{4}^{4}\left(\frac{1}{x}\right)^{4} \\ =C_{4}^{0} x^{8}+C_{4}^{1} x^{6} \cdot\left(\frac{1}{x}\right)+C_{4}^{2} x^{4} \cdot \frac{1}{x^{2}}+C_{4}^{3}\left(x^{2}\right) \cdot\left(\frac{1}{x^{3}}\right)+C_{4}^{4}\left(\frac{1}{x^{4}}\right)=x^{8}+4 x^{5}+6 x^{2}+\frac{4}{x}+\frac{1}{x^{4}}\end{array}\)