a.1/4

b.-7/144

c.25/21

d.17/7

e.80/63

f.9/7

a)1/4

b)-7/144

c)-25/21

d)17/7

e)16/63

f)9/7

a) \(\frac{18}{45}-\frac{4}{12}-\frac{6}{9}-\frac{21}{35}=\frac{2}{5}-\frac{1}{3}-\frac{2}{3}-\frac{3}{5}\)

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

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

\(=\frac{-4}{3}\)

b) \(\frac{4}{3}+\frac{3}{5}+\frac{7}{3}+\frac{2}{5}+\frac{1}{3}=\left(\frac{4}{3}+\frac{7}{3}+\frac{1}{3}\right)+\left(\frac{3}{5}+\frac{2}{5}\right)\)

\(=4+1=5\)

c) \(\frac{1}{3}.\frac{4}{5}.\frac{1}{3}.\frac{6}{5}=\frac{8}{75}\)

d) \(\frac{6}{7}.\frac{8}{13}+\frac{6}{7}.\frac{9}{13}-\frac{3}{13}.\frac{6}{7}\)

\(=\frac{6}{7}.\left(\frac{8}{13}+\frac{9}{13}-\frac{3}{13}\right)\)

\(=\frac{6}{7}.\frac{14}{13}\)

\(=\frac{12}{13}\)

042557

Tự làm đi, lười thế

a) x= 1/4

b) x= -7/144

c) x= 25/6

d) x=17/7

e) x= 80/63

f) x= -45/14

a, \(\dfrac{7}{18}x-\dfrac{2}{3}=\dfrac{5}{18}\)

\(\dfrac{7}{18}x=\dfrac{5}{18}+\dfrac{2}{3}\)

\(\dfrac{7}{18}x=\dfrac{17}{18}\)

\(x=\dfrac{17}{18}\div\dfrac{7}{18}\)

\(x=\dfrac{17}{7}\)

a) \(\dfrac{7}{18}\).x-\(\dfrac{2}{3}\)=\(\dfrac{5}{18}\)

\(\dfrac{7}{18}\).x =\(\dfrac{5}{18}\)+\(\dfrac{2}{3}\)

\(\dfrac{7}{18}\).x = \(\dfrac{17}{18}\)

x = \(\dfrac{17}{18}\) :\(\dfrac{7}{18}\)

x =\(\dfrac{17}{7}\)

b)\(\dfrac{4}{9}\) - \(\dfrac{7}{8}\).x =\(\dfrac{-2}{3}\)

\(\dfrac{7}{8}\).x =\(\dfrac{4}{9}\)-\(\dfrac{-2}{3}\)

\(\dfrac{7}{8}\).x =\(\dfrac{10}{9}\)

x =\(\dfrac{10}{9}\) : \(\dfrac{7}{8}\)

x =\(\dfrac{80}{63}\)

c)\(\dfrac{1}{6}\)+\(\dfrac{-5}{7}\): \(\dfrac{-7}{18}\)

\(\dfrac{1}{6}\)+\(\dfrac{90}{49}\)

\(\dfrac{589}{294}\)

Nếu đúng mình xin 1 cái theo dõi nha bạn

1: x=3/4-1/2=3/4-2/4=1/4

2: x-1/5=2/11

=>x=2/11+1/5=21/55

3: x-5/6=16/42-8/56

=>x-5/6=8/21-4/28=5/21

=>x=5/21+5/6=15/14

4: x/5=5/6-19/30

=>x/5=25/30-19/30=6/30=1/5

=>x=1

5: =>|x|=1/3+1/4=7/12

=>x=7/12 hoặc x=-7/12

6: x=-1/2+3/4

=>x=3/4-1/2=1/4

11: x-(-6/12)=9/48

=>x+1/2=3/16

=>x=3/16-1/2=-5/16

1)x= 1/4

2)x= 2/11+ 1/5

   x= 21/55

3)x - 5/6 = 5/21

   x         = 5/21+5/6

   x         = 15/14

4)x/5 = 5/6 + -19/30

   x:5 = 1/5

   x    = 1/5.5

   x    = 1

5) |x| - 1/4 = 6/18

    |x|           = 6/18 - 1/4

    |x|            =7/12

⇒x= 7/12 hoặc -7/12

6)x = -1/2 +3/4

   x= 1/4

7) x/15 = 3/5 + -2/3

   x:15  = -1/15

  x        = -1/15. 15

  x        = -1

8)11/8 + 13/6 = 85/x  

       85/24      = 85/x

  ⇒      x           = 24

9) x - 7/8 = 13/12

   x          = 13/12 + 7/8

   x          = 47/24

10)x - -6/15 = 4/27  

     x            = 4/27 + (-6/15)

    x             = -34/135

11) -(-6/12)+x = 9/48

                    x= 9/48 - 6/12

                    x = -5/16

12) x - 4/6 = 5/25 + -7/15

      x -4/6  =  -4/15

     x           = -4/15 + 4/6

    x             = 2/5

X + X x \(\dfrac{1}{3}\) + \(\dfrac{5}{18}\) = \(\dfrac{7}{6}\)

X x \(\dfrac{4}{3}\)                 = \(\dfrac{7}{6}-\dfrac{5}{18}\)

X x \(\dfrac{4}{3}\)                 = \(\dfrac{8}{9}\)

X                        = \(\dfrac{8}{9}:\dfrac{4}{3}=\dfrac{2}{3}\)                  

\(x\cdot\left(\dfrac{1}{3}+1\right)=\dfrac{21}{18}-\dfrac{5}{18}=\dfrac{16}{18}=\dfrac{8}{9}\)

\(x=\dfrac{8}{9}:\dfrac{4}{3}=\dfrac{8}{9}\cdot\dfrac{3}{4}=\dfrac{4\cdot2\cdot3}{3\cdot3\cdot4}=\dfrac{2}{3}\)

\(a.\)

\(\frac{4}{9}.x=\frac{1}{9}\)

\(\Rightarrow x=\frac{1}{9}:\frac{4}{9}\)

\(\Rightarrow x=\frac{1}{9}.\frac{9}{4}\)

\(\Rightarrow x=\frac{1}{4}\)

Vậy \(x=\frac{1}{4}\)

\(b.\)

\(\frac{7}{18}.x-\frac{2}{3}=\frac{5}{18}\)

\(\Rightarrow\frac{7}{18}.x=\frac{5}{18}+\frac{2}{3}\)

\(\Rightarrow\frac{7}{18}.x=\frac{5}{18}+\frac{12}{18}\)

\(\Rightarrow\frac{7}{18}.x=\frac{17}{18}\)

\(\Rightarrow x=\frac{17}{18}:\frac{7}{18}\)

\(\Rightarrow x=\frac{17}{18}.\frac{18}{7}\)

\(\Rightarrow x=\frac{17}{7}\)

Vậy \(x=\frac{17}{7}\)

\(c.\)

\(x:-\frac{1}{12}=\frac{7}{12}\)

\(\Rightarrow x=\frac{7}{12}.-\frac{1}{12}\)

\(\Rightarrow x=-\frac{7}{144}\)

Vậy \(x=-\frac{7}{144}\)

\(d.\)

\(\frac{4}{9}-\frac{7}{8}.x=-\frac{2}{3}\)

\(\Rightarrow\frac{7}{8}.x=\frac{4}{9}-\left(-\frac{2}{3}\right)\)

\(\Rightarrow\frac{7}{8}.x=\frac{4}{9}+\frac{2}{3}\)

\(\Rightarrow\frac{7}{8}.x=\frac{4}{9}+\frac{6}{9}\)

\(\Rightarrow\frac{7}{8}.x=\frac{10}{9}\)

\(\Rightarrow x=\frac{10}{9}:\frac{7}{8}\)

\(\Rightarrow x=\frac{10}{9}.\frac{8}{7}\)

\(\Rightarrow x=\frac{80}{63}\)

Vây \(x=\frac{80}{63}\)

\(e.\)

\(-\frac{5}{14}:x=-\frac{3}{10}\)

\(\Rightarrow x=-\frac{5}{14}:-\frac{3}{10}\)

\(\Rightarrow x=-\frac{5}{14}.-\frac{10}{3}\)

\(\Rightarrow x=\frac{5}{7}.\frac{5}{3}\)

\(\Rightarrow x=\frac{25}{21}\)

Vậy \(x=\frac{25}{21}\)

\(g.\)

\(\frac{1}{6}+\frac{-5}{7}:x=-\frac{7}{18}\)

\(\Rightarrow-\frac{5}{7}:x=-\frac{7}{18}-\frac{1}{6}\)

\(\Rightarrow-\frac{5}{7}:x=-\frac{7}{18}-\frac{3}{18}\)

\(\Rightarrow-\frac{5}{7}:x=-\frac{10}{18}\)

\(\Rightarrow-\frac{5}{7}:x=-\frac{5}{9}\)

\(\Rightarrow x=-\frac{5}{7}:-\frac{5}{9}\)

\(\Rightarrow x=-\frac{5}{7}.-\frac{9}{5}\)

\(\Rightarrow x=\frac{9}{7}\)

Vậy \(x=\frac{9}{7}\)