$\begin{array}{l}
{\left( {x\sqrt x - \dfrac{2}{{{x^2}}}} \right)^{10}} = {\left( {{x^{\dfrac{3}{2}}} - \dfrac{2}{{{x^2}}}} \right)^{10}} = \sum\limits_{k = 0}^{10} {C_{10}^k{{\left( {{x^{\dfrac{3}{2}}}} \right)}^{10 - k}}.{{\left( { - \dfrac{2}{{{x^2}}}} \right)}^k}} \\
= \sum\limits_{k = 0}^{10} {C_{10}^k.{x^{\dfrac{{30 - 3k}}{2}}}.{{\left( { - 2} \right)}^k}.{x^{ - 2k}}} = \sum\limits_{k = 0}^{10} {C_{10}^k.{x^{\dfrac{{30 - 3k}}{2} - 2k}}.{{\left( { - 2} \right)}^k}} = \sum\limits_{k = 0}^{10} {C_{10}^k.{x^{\dfrac{{30 - 7k}}{2}}}.{{\left( { - 2} \right)}^k}}
\end{array}$
Số hạng chứa ${x^{\dfrac{{10}}{3}}}$ ứng với $\dfrac{{30 - 7k}}{2} = \dfrac{{10}}{3} \Leftrightarrow 90 - 21k = 20 \Leftrightarrow 70 = 21k \Leftrightarrow k = \dfrac{{10}}{3}$
=> Đề sai, kiểm tra lại đề.
