Tính (2/3)^3-4.(-1 3/4)^2+(-2/3)^3

* Hướng dẫn giải

${\left(\frac{2}{3}\right)}^3-4.{\left(-1\frac{3}{4}\right)}^2+{\left(-\frac{2}{3}\right)}^3={\left(\frac{2}{3}\right)}^3-{\left(\frac{2}{3}\right)}^3-4{\left(-\frac{7}{4}\right)}^2=-4.\frac{49}{16}=-\frac{49}{4}$