Đáp án:
Giải thích các bước giải:
$\left (\dfrac{5}{11}+\dfrac{8}{9} \right ).12-\left (\dfrac{7}{3}-\dfrac{5}{11} \right ).12$
$=\left (\dfrac{5}{11}+\dfrac{8}{9}-\dfrac{7}{3}+\dfrac{5}{11} \right ).12$
$=\left (\dfrac{10}{11}+\dfrac{8}{9}-\dfrac{21}{9} \right ).12$
$=\left (\dfrac{10}{11}-\dfrac{13}{9} \right ).12$
$=\left (\dfrac{90}{99}-\dfrac{143}{99} \right ).12$
$=\dfrac{-53}{99}.12$
$=\dfrac{-636}{99}$
$=-\dfrac{212}{33}$
Chúc em học tốt.
