Giải

a)-5/18+5/9-11/36

=(-10/36)+20/36-11/36

=-1/36

b)-39/44:13/11

=-39/44.11/13

=-3/4

a) \(\frac{-5}{18}+\frac{5}{9}-\frac{11}{36}\)

= \(-\frac{10}{36}+\frac{20}{36}-\frac{11}{36}\)

= \(-\frac{1}{36}\)

b) \(-\frac{39}{44}:\frac{13}{11}\)

= \(-\frac{39}{44}.\frac{11}{13}\)

= \(\frac{\left(-39\right).11}{44.13}\)

= \(\frac{\left(-3\right).13.11}{11.4.13}\)

= \(-\frac{3}{4}\)

trả lời 

câu 1 \(\frac{-1}{36}\)

câu 2 \(\frac{-3}{4}\)

hok tốt

Ghi đầy đủ nha

bn có thể ghi rõ ràng đc ko?

a)\(-\dfrac{3}{7}+\dfrac{5}{13}+\dfrac{3}{7}\) 

=\(\left(-\dfrac{3}{7}+\dfrac{3}{7}\right)+\dfrac{5}{13}\) 

=\(0+\dfrac{5}{13}\) 

=\(\dfrac{5}{13}\)

\(1.\) \(\dfrac{7}{36}-\dfrac{8}{-9}+\dfrac{-2}{3}=\dfrac{7}{36}+\dfrac{8}{9}-\dfrac{2}{3}=\dfrac{7+32-24}{36}=\dfrac{5}{12}.\)

\(2.\) \(\dfrac{-1}{2}+\dfrac{3}{7}-\dfrac{1}{9}+\dfrac{-7}{18}+\dfrac{4}{7}=\dfrac{-9-2-7}{18}+\dfrac{4+3}{7}=\dfrac{-18}{18}+\dfrac{7}{7}=-1+1=0.\)

\(3.\) \(-\dfrac{10}{3}+\dfrac{13}{10}-\dfrac{1}{6}+\dfrac{1}{10}=\dfrac{13+1}{10}+\dfrac{-20-1}{6}=\dfrac{14}{10}+\dfrac{-21}{6}=\dfrac{7}{5}-\dfrac{7}{2}=-\dfrac{21}{10}.\)

\(4.\) \(\dfrac{10}{17}-\dfrac{5}{13}-\left(-\dfrac{7}{17}\right)-\dfrac{8}{13}+\dfrac{11}{25}=\dfrac{10+7}{17}+\dfrac{-5-8}{13}+\dfrac{11}{25}=\dfrac{17}{17}-\dfrac{13}{13}+\dfrac{11}{25}=\dfrac{11}{25}.\)

1: \(=\dfrac{7}{36}+\dfrac{32}{36}+\dfrac{-24}{36}=\dfrac{15}{36}=\dfrac{5}{12}\)

2: \(=\left(-\dfrac{1}{2}-\dfrac{1}{9}-\dfrac{7}{18}\right)+\dfrac{3}{7}+\dfrac{4}{7}\)

\(=\dfrac{-9-2-7}{18}+1=-1+1=0\)

3: \(=\left(-\dfrac{10}{3}-\dfrac{1}{6}\right)+\dfrac{14}{10}\)

\(=-\dfrac{21}{6}+\dfrac{14}{10}=\dfrac{-7}{2}+\dfrac{14}{10}=\dfrac{-35+14}{10}=-\dfrac{21}{10}\)

4: \(=\left(\dfrac{10}{17}+\dfrac{7}{17}\right)-\left(\dfrac{5}{13}+\dfrac{8}{13}\right)+\dfrac{11}{25}=\dfrac{11}{25}\)

1)  10 - 3 ( x - 1 ) = -5

      3 ( x - 1 ) = 10 - ( - 5 )

      3 ( x - 1 ) =  15

          x - 1   = 15 : 3

          x - 1   = 5

         x         = 5 + 1

        x         = 6

2) 3x + 75 = - 15

    3x        = - 15 - 75

    3x        = - 90

      x       = -90 : 3

     x        = -30

4)  12 - ( x - 7 ) = - 8

             x - 7   = 12 - (- 8 )

             x - 7   = 20

             x        = 20 + 7

            x         = 27

5)  x + 75 = 15

    x         = 15 - 75

    x         = -60

7)  2x + 18 = 10

     2x        = 10 - 18

     2x        = -8

       x        = - 8 : 2

       x       = -4

8)  26 - 3x = 5

            3x = 26 - 5

            3x = 21

              x  = 21: 3

              x = 7

9) x - 12 = - 15

    x       = -15 + 12

   x         =-3

 10 ) 24 - 2 ( x + 5 ) = 38

              2 ( x+ 5 )  = 24 - 38

              2 ( x + 5 ) = - 14

                  x + 5    = -14 : 2

                  x + 5    = -7

                  x          = -7 - 5

                  x          = -12

còn là bạn tự làm tiếp nhé ! bạn gửi nhiều cầu qua bạn chỉ nên gửi ít một thời như vậy khó có thể giải làm bạn ạ!

25 - 5 (3- x) = 15 

25 - 5 (3-x) = 15  

      5 (3-x) = 25 -15 

      5 (3-x) = 10 

     3 - x = 10 : 5 

    3 - x = 2 

         x = 3 - 2 

          x = 1

a: \(\left(-\dfrac{5}{6}+\dfrac{2}{5}\right):\dfrac{3}{8}+\left(\dfrac{4}{5}-\dfrac{11}{30}\right):\dfrac{3}{8}\)

\(=\left(-\dfrac{5}{6}+\dfrac{2}{5}\right)\cdot\dfrac{8}{3}+\left(\dfrac{4}{5}-\dfrac{11}{30}\right)\cdot\dfrac{8}{3}\)

\(=\dfrac{8}{3}\left(-\dfrac{5}{6}+\dfrac{2}{5}+\dfrac{4}{5}-\dfrac{11}{30}\right)\)

\(=\dfrac{8}{3}\cdot\dfrac{-25+36-11}{30}\)

=0

b: \(\left(-\dfrac{3}{4}+\dfrac{2}{5}\right):\dfrac{3}{7}+\left(\dfrac{3}{5}+\dfrac{-1}{4}\right):\dfrac{3}{7}\)

\(=\left(-\dfrac{3}{4}+\dfrac{2}{5}\right)\cdot\dfrac{7}{3}+\left(\dfrac{3}{5}-\dfrac{1}{4}\right)\cdot\dfrac{7}{3}\)

\(=\dfrac{7}{3}\left(-\dfrac{3}{4}+\dfrac{2}{5}+\dfrac{3}{5}-\dfrac{1}{4}\right)\)

\(=\dfrac{7}{3}\cdot0=0\)

c: \(\dfrac{-13}{18}\cdot\dfrac{5}{8}+\dfrac{-5}{18}\cdot\dfrac{2}{9}+\dfrac{-13}{18}\cdot\dfrac{3}{8}+\dfrac{-5}{18}\cdot\dfrac{7}{9}\)

\(=\left(-\dfrac{13}{18}\cdot\dfrac{5}{8}+\dfrac{-13}{18}\cdot\dfrac{3}{8}\right)+\left(-\dfrac{5}{18}\cdot\dfrac{2}{9}+\dfrac{-5}{18}\cdot\dfrac{7}{9}\right)\)

\(=-\dfrac{13}{18}\left(\dfrac{5}{8}+\dfrac{3}{8}\right)+\dfrac{-5}{18}\left(\dfrac{2}{9}+\dfrac{7}{9}\right)\)

\(=-\dfrac{13}{18}-\dfrac{5}{18}=-\dfrac{18}{18}=-1\)

d: Sửa đề: \(\dfrac{-11}{19}\cdot\dfrac{4}{9}+\dfrac{-8}{19}\cdot\dfrac{3}{7}+\dfrac{-11}{19}\cdot\dfrac{5}{9}+\dfrac{-8}{19}\cdot\dfrac{4}{7}\)

\(=\left(-\dfrac{11}{19}\cdot\dfrac{4}{9}+\dfrac{-11}{19}\cdot\dfrac{5}{9}\right)+\left(\dfrac{-8}{19}\cdot\dfrac{3}{7}+\dfrac{-8}{19}\cdot\dfrac{4}{7}\right)\)

\(=-\dfrac{11}{19}\left(\dfrac{4}{9}+\dfrac{5}{9}\right)+\dfrac{-8}{19}\left(\dfrac{3}{7}+\dfrac{4}{7}\right)\)

\(=-\dfrac{11}{19}-\dfrac{8}{19}=-\dfrac{19}{19}=-1\)

\(a.\left(-\dfrac{5}{6}+\dfrac{2}{5}\right):\dfrac{3}{8}+\left(\dfrac{4}{5}-\dfrac{11}{30}\right):\dfrac{3}{8}\)

\(=\left(-\dfrac{13}{30}\right):\dfrac{3}{8}+\dfrac{13}{30}:\dfrac{3}{8}\)

\(=\left[\left(-\dfrac{13}{30}+\dfrac{13}{30}\right)\right]:\dfrac{3}{8}\)

\(=0:\dfrac{3}{8}=0\)

\(b.\left(-\dfrac{3}{4}+\dfrac{2}{5}\right):\dfrac{3}{7}+\left(\dfrac{3}{5}+-\dfrac{1}{4}\right):\dfrac{3}{7}\)

\(=\left(-\dfrac{7}{20}\right):\dfrac{3}{7}+\dfrac{7}{20}:\dfrac{3}{7}\)

\(=\left[\left(-\dfrac{7}{20}+\dfrac{7}{20}\right)\right]:\dfrac{3}{7}=0:\dfrac{3}{7}=0\)

\(c.-\dfrac{13}{18}.\dfrac{5}{8}+-\dfrac{5}{18}.\dfrac{2}{9}+-\dfrac{13}{18}.\dfrac{3}{8}+-\dfrac{5}{18}.\dfrac{7}{9}\)

\(=\left(\dfrac{5}{8}+\dfrac{3}{8}\right).-\dfrac{13}{18}+\left(\dfrac{2}{9}+\dfrac{7}{9}\right).-\dfrac{5}{18}\)

\(=1.-\dfrac{13}{18}+1.-\dfrac{5}{18}=-\dfrac{13}{18}+-\dfrac{5}{18}=-1\)

\(d.-\dfrac{11}{19}.\dfrac{4}{9}+\dfrac{-8}{19}.\dfrac{3}{7}+-\dfrac{11}{19}.\dfrac{5}{9}+-\dfrac{9}{19}.\dfrac{4}{7}\)

\(=\left(\dfrac{4}{9}+\dfrac{5}{9}\right).-\dfrac{11}{19}+-\dfrac{24}{133}+-\dfrac{36}{133}\)

\(=-\dfrac{11}{19}+-\dfrac{60}{133}=-\dfrac{137}{133}\)

a  \(\dfrac{5}{12}\times\dfrac{4}{9}\) + \(\dfrac{4}{9}\times\dfrac{7}{12}\)

= \(\dfrac{4}{9}\times\left(\dfrac{5}{12}+\dfrac{7}{12}\right)\)

= \(\dfrac{4}{9}\times\dfrac{12}{12}\)

= \(\dfrac{4}{9}\)

b(\(\dfrac{13}{21}\times\dfrac{7}{8}-\dfrac{12}{21}\times\dfrac{7}{8}\)) x 12 

(\(\dfrac{7}{8}\times\left(\dfrac{13}{21}-\dfrac{12}{21}\right)\))x 12

\(\dfrac{7}{8}\times\dfrac{1}{21}\) x 12

\(\dfrac{139}{14}\)

\(\dfrac{7}{11}+\dfrac{3}{4}+\dfrac{4}{11}+\dfrac{8}{17}+\dfrac{1}{4}+\dfrac{18}{34}\)

=\(\left(\dfrac{7}{11}+\dfrac{4}{11}\right)+\left(\dfrac{3}{4}+\dfrac{1}{4}\right)\) + \(\dfrac{18}{34}\) 

=1 + 1 + \(\dfrac{18}{34}\)

=\(\dfrac{34}{17}\)

2)a 3,71 + (632 - x) = 415 

                  632 - x= 415 - 3,71 

                  632 -x = 411,59

                          x = 632 - 411,59 

                          x = 220,41

b, 140 : (5x \(x\) - 15) = 4 

              5x \(x\) - 15 = 140 : 4

             5x \(x\) - 15 = 35 

              5x \(x\) = 35 + 15 

             5x \(x\) = 50 

                  \(x\) = 50 : 5 

                 \(x\) = 10

  12 giờ  6 phút 

+ 

   6 giờ 52 phút

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  18 giờ 58 phút

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9 năm 3 tháng - 6 năm 11 tháng = 111 tháng - 83 tháng

  111 tháng

-

    83 tháng

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    28 tháng = 2 năm 4 tháng

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  13 phút   36 giây

x

                   3

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   39 phút 108 giây = 40 phút 48 giây

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a, 18 giờ 58 phút
b, 2 năm 4 tháng
c, 40 năm 56 tháng
d, 3 phút 2 giây