Đáp án:
$\dfrac{49}{4}$
Giải thích các bước giải:
$(\dfrac{2}{3})^3-4×(-1\dfrac{3}{4})^2+(\dfrac{-2}{3})^3$
$=\dfrac{8}{27}-4×(\dfrac{-7}{4})^2+\dfrac{-8}{27}$
$=\dfrac{8}{27}-4×\dfrac{49}{16}+\dfrac{-8}{27}$
$=\dfrac{8}{27}-\dfrac{49}{4}+\dfrac{-8}{27}$
$=\dfrac{8}{27}+\dfrac{-49}{4}+\dfrac{-8}{27}$
$=(\dfrac{8}{27}+\dfrac{-8}{27})+\dfrac{-49}{4}$
$=0+\dfrac{-49}{4}$
$=\dfrac{-49}{4}$