Question

A)(3 1/3+2,5):(3 1/6-4 1/5)-11/31.

b)3/21-12/47+27/53:4/41-16/47+36/53.

dề bài:tính giá trị biểu thức.

Answer 1

a, \(\left(3\dfrac{1}{3}+2,5\right):\left(3\dfrac{1}{6}-4\dfrac{1}{5}\right)-\dfrac{11}{31}\)

\(=\left(\dfrac{10}{3}+2,5\right):\left(\dfrac{19}{6}-\dfrac{21}{5}\right)-\dfrac{11}{31}\)

\(=\dfrac{35}{6}:\dfrac{-31}{30}-\dfrac{11}{31}=-\dfrac{175}{31}-\dfrac{11}{31}=-6\)

b,Sửa đề: \(\dfrac{\dfrac{3}{21}-\dfrac{12}{47}+\dfrac{27}{53}}{\dfrac{4}{21}-\dfrac{16}{47}+\dfrac{36}{53}}==\dfrac{\dfrac{1}{3}.\left(\dfrac{1}{21}-\dfrac{4}{47}+\dfrac{9}{53}\right)}{\dfrac{1}{4}.\left(\dfrac{1}{21}-\dfrac{4}{47}+\dfrac{9}{53}\right)}\)

\(=\dfrac{\dfrac{1}{3}}{\dfrac{1}{4}}=\dfrac{4}{3}\)

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