Đáp án:
$-4$
Giải thích các bước giải:
$\left[\left(\dfrac{-1}{3}\right)^{\large 2}\cdot\dfrac{27}{7}+\sqrt{\dfrac{4}{49}}-3\right]:\dfrac47\\=\left(\dfrac19\cdot\dfrac{27}{7}+\dfrac27-3\right):\dfrac47\\=\left(\dfrac37+\dfrac27-3\right):\dfrac47\\=\left(\dfrac57-3\right):\dfrac47\\=\dfrac{-16}{7}:\dfrac47\\=-4$