Câu hỏi của Jenny Jenny

Question

Thực hiện phép tính:

$\dfrac{11}{4}.\left(-0,4\right)+7,2:\dfrac{9}{11}$

3.($\dfrac{5}{6}-2\dfrac{1}{12}$)

Nguyễn Lê Phước Thịnh · Accepted Answer

a: $=\dfrac{11}{4}\cdot\dfrac{-2}{5}+\dfrac{36}{5}\cdot\dfrac{11}{9}=\dfrac{11}{9}\cdot\dfrac{34}{5}=\dfrac{374}{45}$

b: $=3\cdot\left(\dfrac{5}{6}-\dfrac{25}{12}\right):\dfrac{30}{7}-\dfrac{1}{4}\cdot\dfrac{-2}{3}$

$=3\cdot\dfrac{7}{30}\cdot\dfrac{-15}{12}+\dfrac{1}{6}$

$=\dfrac{7}{10}\cdot\dfrac{-5}{4}+\dfrac{1}{6}$

$=\dfrac{-7}{8}+\dfrac{1}{6}=\dfrac{-21+4}{24}=\dfrac{-17}{24}$

Câu trả lời:

a: $=\dfrac{11}{4}\cdot\dfrac{-2}{5}+\dfrac{36}{5}\cdot\dfrac{11}{9}=\dfrac{11}{9}\cdot\dfrac{34}{5}=\dfrac{374}{45}$

b: $=3\cdot\left(\dfrac{5}{6}-\dfrac{25}{12}\right):\dfrac{30}{7}-\dfrac{1}{4}\cdot\dfrac{-2}{3}$

$=3\cdot\dfrac{7}{30}\cdot\dfrac{-15}{12}+\dfrac{1}{6}$

$=\dfrac{7}{10}\cdot\dfrac{-5}{4}+\dfrac{1}{6}$

$=\dfrac{-7}{8}+\dfrac{1}{6}=\dfrac{-21+4}{24}=\dfrac{-17}{24}$