,,,,, D = {1; 9; 10; 12}

Tập hợp D là?

A. D = {8; 9; 10; 12}     

B. D = {1; 9; 10}     

C. D = {9; 10; 12}     

D. D = {1; 9; 10; 12}

a)2/9-(-4/9)=6/9=2/3

b)(-1/24+0,25+1 1/12):(-1/2)2

=(-1/24+6/24+26/24):(-1/2).2

=31/24.-2.2

=-31/12.2

=-31/6

c)3/13.(-5/9)+10/13.(-5/9)+(-4/9)

=-5/9(3/13+10/13)+(-4/9)

=-5/9.1+(-4/9)

=-1

1.

a)2/9-(-4/9)=6/9 

b)(-1/24+0,25+11/12):(-1/2)2

=1,125:-1

=-1,125

c) 3/13.-5/9+10/13.-5/9+-4/9

=-5/9.(3/13+10/13)+4/9

=5/9.1+4/9

=5/9+4/9

=9/9=1

2.

a)-41/5:x=51/4

           x=51/41.-41/5

           x=-1

    vậy x=-1                                    

b)7/12-5/12.x=1/12

          5/12.x=1/12+7/12

          5/12.x=6/12

                 x=6/12:5/12

                 x=6/12.12/5

                 x=6/5

  vậy x=6/5

1 - 7/9 = 2/9

7/9 + 9/12 = 55/36

12 : 2/3 = 18

9/12 : 3 = 1/4

\(1-\frac{7}{9}=\frac{9}{9}-\frac{7}{9}=\frac{2}{9}\)

\(\frac{7}{9}+\frac{9}{12}=\frac{28}{36}+\frac{27}{36}=\frac{55}{36}\)

\(12:\frac{2}{3}=12x\frac{3}{2}=\frac{36}{2}=18\)

\(\frac{9}{12}:3=\frac{9}{12}x\frac{1}{3}=\frac{9}{36}=\frac{1}{4}\)

1 - 7/9 = 2/9

7/9 + 9/12 = 55/36

12 : 2/3 = 18

9/12 : 3 = 1/4

77

77

77

a)=\(-\dfrac{3}{8}\)

b)=\(\dfrac{13}{12}\)

c)=\(-\dfrac{7}{36}\)

d)=\(-\dfrac{5}{36}\)

\(\dfrac{1}{8}-\dfrac{1}{2}=\dfrac{1-4}{8}=\dfrac{-3}{8}.\\ \dfrac{-11}{12}-\left(-2\right)=\dfrac{-11}{12}+2=\dfrac{13}{12}.\\ \dfrac{-1}{12}-\dfrac{1}{9}=\dfrac{-7}{36}.\\ \dfrac{-5}{9}-\dfrac{-5}{12}=\dfrac{-5}{36}.\)

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