$\Big(3x^2-\dfrac{2}{x^3}\Big)^{10}$
$=\sum\limits_{k=0}^{10}C_{10}^k.3^{10-k}x^{20-2k}.(-2)^k.\dfrac{1}{x^{3k}}$
$=\sum\limits_{k=0}^{10}C_{10}^k.3^{10-k}.(-2)^k.x^{20-5k}$
$\Rightarrow 20-5k=5\Leftrightarrow k=3$
Vậy hệ số là:
$C_{10}^3.3^7.(-2)^3=-2099520$