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6 tháng 8 2021

a) \(A=\dfrac{2}{3}+\dfrac{3}{4}.\left(\dfrac{-4}{9}\right)=\dfrac{2}{3}-\dfrac{1}{3}=\dfrac{1}{3}\)

b) \(B=2\dfrac{3}{11}.1\dfrac{1}{12}.\left(-2,2\right)=\dfrac{25}{11}.\dfrac{13}{12}.\dfrac{-11}{5}=-\dfrac{65}{12}\)

c) \(C=\left(\dfrac{3}{4}-0,2\right)\left(0,4-\dfrac{4}{5}\right)=\left(\dfrac{3}{4}-\dfrac{1}{5}\right)\left(\dfrac{2}{5}-\dfrac{4}{5}\right)=\dfrac{11}{20}\left(\dfrac{-2}{5}\right)=\dfrac{-11}{50}\)

6 tháng 8 2021

A = 2/3 + -1/3

    = 1/3

B = 25/11 . 13/12 . (-2,2)

    = 325/132 . (-2,2)

    = -65/12

C = 11/20 . -2/5

    = -11/50

Chúc bạn học tốt!! ^^

    = -

23 tháng 6 2021

1/ 

a, \(A=\dfrac{2}{3}+\dfrac{3}{4}.\left(-\dfrac{4}{9}\right)=\dfrac{2}{3}-\dfrac{1}{3}=\dfrac{1}{3}\)

b, \(B=2\dfrac{3}{11}.\dfrac{11}{12}.\left(-2,2\right)=\dfrac{25}{11}.\dfrac{11}{12}.\left(-\dfrac{11}{5}\right)=-\dfrac{55}{12}\)

c, \(C=\left(\dfrac{3}{4}-0,2\right):\left(0,4-\dfrac{4}{5}\right)=\left(\dfrac{3}{4}-\dfrac{1}{5}\right):\left(\dfrac{2}{5}-\dfrac{4}{5}\right)=\dfrac{11}{20}:\left(-\dfrac{2}{5}\right)=-\dfrac{11}{8}\)

2/ 

a, \(\dfrac{11}{12}-x=\dfrac{2}{3}+\dfrac{1}{4}\\ \Rightarrow\dfrac{11}{12}-x=\dfrac{11}{12}\\ \Rightarrow x=0\)

b, \(2x\left(x-\dfrac{1}{7}\right)=0\\ \Leftrightarrow\left\{{}\begin{matrix}2x=0\\x-\dfrac{1}{7}=0\end{matrix}\right.\\ \Leftrightarrow\left\{{}\begin{matrix}x=0\\x=\dfrac{1}{7}\end{matrix}\right.\)

c, \(\dfrac{3}{4}+\dfrac{1}{4}:x=\dfrac{2}{5}\\ \Rightarrow\dfrac{1}{4}:x=-\dfrac{7}{20}\\ \Rightarrow x=-\dfrac{5}{7}\)

24 tháng 6 2021

câu b bài 1 là 1 1/12 là hỗn số nhen

\(A=\dfrac{2}{3}+\dfrac{3}{4}\cdot\dfrac{-4}{9}=\dfrac{2}{3}-\dfrac{1}{3}=\dfrac{1}{3}=\dfrac{100}{300}\)

\(B=\dfrac{25}{11}\cdot\dfrac{13}{12}\cdot\dfrac{-11}{5}=\dfrac{-65}{12}=\dfrac{-1625}{300}\)

\(C=\left(\dfrac{3}{4}-\dfrac{1}{5}\right)\cdot\left(\dfrac{2}{5}-\dfrac{4}{5}\right)=\dfrac{11}{20}\cdot\dfrac{-2}{5}=\dfrac{-22}{100}=\dfrac{-11}{50}=\dfrac{-66}{300}\)

Vì -1625<-66<100

nên B<C<A

a: Ta có: \(0,\left(3\right)+\dfrac{10}{3}+0,4\left(2\right)\)

\(=\dfrac{1}{3}+\dfrac{10}{3}+\dfrac{4}{9}\)

\(=\dfrac{33}{9}+\dfrac{4}{9}=\dfrac{37}{9}\)

b: Ta có: \(\dfrac{4}{9}+1.2\left(31\right)-0,\left(13\right)\)

\(=\dfrac{4}{9}+\dfrac{1219}{990}-\dfrac{13}{99}\)

\(=\dfrac{440}{990}+\dfrac{1219}{990}-\dfrac{130}{990}\)

\(=\dfrac{139}{90}\)

c: Ta có: \(2,\left(4\right)\cdot\dfrac{3}{11}\)

\(=\dfrac{22}{9}\cdot\dfrac{3}{11}\)

\(=\dfrac{2}{3}\)

d: Ta có: \(-0,\left(3\right)+\dfrac{1}{3}\)

\(=-\dfrac{1}{3}+\dfrac{1}{3}\)

=0

26 tháng 6 2017

a)\(A=\frac{2}{3}+\frac{3}{4}.-\frac{4}{9}\)

   \(A=\frac{2}{3}-\frac{1}{3}\)

     \(A=\frac{1}{3}\)

b)\(B=2\frac{3}{11}.1\frac{1}{12}.\left(-2,2\right)\)

    \(B=\frac{325}{132}.\left(-2,2\right)\)

      \(B=-\frac{65}{12}\)

c)\(C=\left(\frac{3}{4}-0,2\right).\left(0,4-\frac{4}{5}\right)\)

    \(C=\frac{11}{20}.-\frac{2}{5}\)

     \(C=-\frac{11}{50}\)

              Ta có:\(A=\frac{1}{3}=\frac{100}{300}\)

                        \(B=-\frac{65}{12}=-\frac{1625}{300}\)

                         \(C=-\frac{11}{50}=-\frac{660}{300}\)

                                  Vì \(-\frac{1625}{300}< -\frac{660}{300}< \frac{100}{3}\)

      Vậy \(B< C< A\)

                          

26 tháng 6 2017

A= 2/3-1/3=1/3 = 0,333..

B=25/11.13/12.(-2,2)= -65/12= -5,41666...

C= 11/20.(-2/5) =-11/50=-0,22

=> B < C < A

12 tháng 7 2018

\(A=\frac{2}{3}+\frac{3}{4}\left(\frac{-4}{9}\right)\)

\(A=\frac{2}{3}+\frac{-1}{3}\)

\(A=\frac{1}{3}\)

\(B=\frac{2}{5}+\frac{3}{5}\div\left(-2\right)\)

\(B=\frac{2}{5}+\frac{-3}{10}\)

\(B=\frac{1}{10}\)

\(C=2\frac{3}{11}\cdot1\frac{1}{12}\cdot\left(-2,2\right)\)

\(C=\frac{325}{132}\cdot\left(-2,2\right)\)

\(C=\frac{-65}{12}\)

\(D=\left(\frac{3}{4}-0,2\right)\left(0,4-\frac{4}{5}\right)\)

\(D=\frac{11}{20}\cdot\frac{-2}{5}\)

\(D=\frac{-11}{50}\)

27 tháng 9 2021

a) \(=\dfrac{\left(-1\right)^4}{3^4}=\dfrac{1}{81}\)

b) \(=\dfrac{\left(-9\right)^3}{4^3}=\dfrac{-729}{64}\)

c) \(=\left(-\dfrac{2}{10}\right)^2=\left(-\dfrac{1}{5}\right)^2=\dfrac{1}{25}\)

d) \(=1\)

27 tháng 9 2021

\(a,=\dfrac{1}{81}\\ b,=\dfrac{729}{64}\\ c,=0,04\\ d,=1\)