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30 tháng 3 2022

\(-\dfrac{3}{7}\cdot\dfrac{12}{25}-\dfrac{3}{7}\cdot\dfrac{13}{25}+2\dfrac{2}{7}\)

\(=\dfrac{3}{7}\cdot\left(-\dfrac{12}{25}\right)-\dfrac{3}{7}\cdot\dfrac{13}{25}+\dfrac{16}{7}\)

\(=\dfrac{3}{7}\cdot\left(-\dfrac{12}{25}-\dfrac{13}{25}\right)+\dfrac{16}{7}\)

\(=\dfrac{3}{7}\cdot\left(-1\right)+\dfrac{16}{7}\)

\(=-\dfrac{3}{7}+\dfrac{16}{7}\)

\(=\dfrac{13}{7}\)

30 tháng 3 2022

` -3/7 . 12/25 - 3/7 . 13/25 + 2(2)/7 = -3/7 ( 12/25 + 13/25 ) + 2(2)/7 = -3/7 . 25/25 + 2(2)/7 = -3/7 . 1 + 2(2)/7 = -3/7 + 16/7 = 13/7 `

23 tháng 5 2024

  \(\dfrac{1}{2}+\dfrac{3}{4}-\left(\dfrac{3}{4}-\dfrac{4}{5}\right)\)

=\(\dfrac{1}{2}+\dfrac{3}{4}-\dfrac{3}{4}+\dfrac{4}{5}\)

=\(\left(\dfrac{1}{2}+\dfrac{4}{5}\right)+\left(\dfrac{3}{4}-\dfrac{3}{4}\right)\) 

=\(\left(\dfrac{5}{10}+\dfrac{8}{10}\right)+0\)

=\(\dfrac{13}{10}\)

23 tháng 5 2024

\(-\dfrac{7}{25}.\dfrac{11}{13}+\left(-\dfrac{7}{25}\right).\dfrac{2}{13}-\dfrac{18}{25}\)

=\(-\dfrac{7}{25}.\cdot\left(\dfrac{11}{13}+\dfrac{2}{13}\right)-\dfrac{18}{25}\) 

=\(-\dfrac{7}{25}.1-\dfrac{18}{25}\) 

=\(-\dfrac{7}{25}-\dfrac{18}{25}\) 

=\(-\dfrac{25}{25}\) = \(-1\)

5 tháng 4 2016

a) -7/25 . 11/13 + -7/25 . 2/13 - 18/25=-1

b) 5/7 . 1/3 - 5/7 . 1/4 - 5/7 . 1/12=0

c) 5 + 2/5 . 4+ 2/7 + 5 + 5/7 . 5+ 2/5=18

d) 75% - 3/2 + 0,5 - [ -1/2]^2=-1/2

5 tháng 4 2016

a) -7/25 x 11/13 + -7/25 x 2/13 - 18/25 = -1

b) 5/7 x 1/3 - 5/7 x 1/4 - 5/7 x 1/12=0

c) 5 + 2/5 x 4+ 2/7 + 5 + 5/7 x 5+ 2/5=15.85714285

 

a) Ta có: \(A=\dfrac{2}{7}+\dfrac{-3}{8}+\dfrac{11}{7}+\dfrac{1}{3}+\dfrac{1}{7}+\dfrac{5}{-8}\)

\(=\left(\dfrac{2}{7}+\dfrac{11}{7}+\dfrac{1}{7}\right)+\left(\dfrac{-3}{8}+\dfrac{-5}{8}\right)+\dfrac{1}{3}\)

\(=2-1+\dfrac{1}{3}\)

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

b) Ta có: \(B=\dfrac{-3}{8}+\dfrac{12}{25}+\dfrac{5}{-8}+\dfrac{2}{-5}+\dfrac{13}{25}\)

\(=\left(\dfrac{-3}{8}+\dfrac{-5}{8}\right)+\left(\dfrac{12}{25}+\dfrac{13}{25}\right)+\dfrac{-2}{5}\)

\(=-1+1+\dfrac{-2}{5}\)

\(=-\dfrac{2}{5}\)

Giải:

A= 2/7+ -3/8 +11/7 +1/3 + 1/7 + 5/-8

A= (2/7+11/7+1/7)+(-3/8+-5/8)+1/3

A= 2+ (-1) + 1/3

A= 1+1/3

A= 4/3

 

B= -3/8 + 12/25 + 5/-8 + 2/-5 + 13/25

B= (-3/8+-5/8) + (12/25+13/25) + -2/5

B= -1 + 1 + -2/5

B=-2/5

Chúc bạn học tốt!

14 tháng 5 2017

1 a)38000             b)1/8                c)3/2          d)9/17

2  a) 0.64           b)0.025                 c)-1

14 tháng 5 2017

Bài giải:

Câu 1: a, \(\left(-2\right).4.5.38.\left(-25\right)\)

\(=\left[\left(-2\right).5\right].\left[4.\left(-25\right)\right].38\)

\(=\left(-10\right).\left(-100\right).38\)

\(=1000.38=38000\)

b,\(\frac{1}{3}+\frac{3}{8}-\frac{7}{12}\)

\(=\left(\frac{1}{3}+\frac{3}{8}\right)-\frac{7}{12}\)

\(=\frac{17}{24}-\frac{7}{12}=\frac{1}{8}\)

c, \(\frac{-5}{8}.\frac{5}{12}+\frac{-5}{8}.\frac{7}{12}+2\frac{1}{8}\)

\(=\frac{-5}{8}.\left(\frac{5}{12}+\frac{7}{12}\right)+\frac{17}{8}\)

\(=\frac{-5}{8}.1+\frac{17}{8}\)

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

Câu 2: a, \(x-\frac{2}{5}=0,24\)

               \(x-0,4=0,24\)

               \(x=0,24+0,4\)

         \(\Rightarrow x=0,64\left(\frac{16}{25}\right)\)

b,\(\frac{2}{3}.x+\frac{1}{12}=\frac{1}{10}\)

\(\frac{2}{3}.x=\frac{1}{10}-\frac{1}{12}\)

\(\frac{2}{3}.x=\frac{1}{60}\)

       \(x=\frac{1}{60}:\frac{2}{3}\)

   \(\Rightarrow x=\frac{1}{40}\)

c, \(\left(3\frac{1}{2}-2x\right).1\frac{1}{3}=7\frac{1}{3}\)

\(\frac{7}{2}-2x=\frac{22}{3}:\frac{4}{3}\)

\(\frac{7}{2}-2x=\frac{11}{2}\)

            \(2x=\frac{7}{2}-\frac{11}{2}\)

             \(2x=-2\)

            \(\Rightarrow x=-2:2\)

                  \(x=-1\)

10 tháng 1 2018

A=2/7+-3/8+11/7+1/3+1/7+5/-8

A=(2/7 + 1/7 + 11/7) + (-3/8 + 5/-8) + 1/3

A=2 + (-1) + 1/3

A=1 + 1/3

A=4/3

B=-3/8+12/25+5/-8+2/-5+13/25

B=(-3/8 + 5/-8) + (12/25 + 13/25) + 2/-5

B=-1 + 1 + 2/-5

B=-2/5

4 tháng 1 2016

1)-73

2)-5

3)-64

4)-56

5)9

6)-20

7)6

8)-2

Tick nha

 

 

4 tháng 1 2016

mk ra kết quả thôi nha

 

16 tháng 3 2022

`Answer:`

a. \(-\frac{17}{30}-\frac{11}{-15}+-\frac{7}{12}\)

\(=-\frac{17}{30}+\frac{11}{15}-\frac{7}{12}\)

\(=-\frac{17}{30}+\frac{22}{30}-\frac{7}{12}\)

\(=\frac{1}{6}-\frac{7}{12}\)

\(=-\frac{5}{12}\)

b. \(-\frac{5}{9}+\frac{5}{9}:\left(\frac{5}{3}-\frac{25}{12}\right)\)

\(=-\frac{5}{9}+\frac{5}{9}:\left(-\frac{5}{12}\right)\)

\(=\frac{5}{9}.\left(-1\right)+\frac{5}{9}.\left(-\frac{12}{5}\right)\)

\(=\frac{5}{9}.\left(-1-\frac{12}{5}\right)\)

\(=\frac{5}{9}.\frac{-17}{5}\)

\(=-\frac{17}{9}\)

c. \(-\frac{7}{25}.\frac{11}{13}+-\frac{7}{25}-\frac{2}{13}-\frac{18}{25}\)

\(=\frac{77}{325}-\left(\frac{7}{25}+\frac{18}{25}\right)-\frac{2}{13}\)

\(=\frac{77}{325}-1-\frac{2}{13}\)

\(=-\frac{452}{325}\)