\(a.\dfrac{1}{2}:3+x=\dfrac{14}{5}\)

\(\dfrac{1}{6}+x=\dfrac{14}{5}\)

\(=>x=\dfrac{79}{30}\)

\(b.\dfrac{8}{5}:x:\dfrac{7}{4}=\dfrac{11}{6}\)

\(\left(\dfrac{8}{5}\cdot\dfrac{4}{7}\right):x=\dfrac{11}{6}\)

\(\dfrac{32}{35}:x=\dfrac{11}{6}\)

\(x=\dfrac{192}{385}\)

\(c.\dfrac{24}{10}+x:\dfrac{3}{4}=\dfrac{11}{3}\)

\(x:\dfrac{3}{4}=\dfrac{11}{3}-\dfrac{24}{10}\)

\(x:\dfrac{3}{4}=\dfrac{38}{30}\)

\(=>x=\dfrac{19}{20}\)

\(a,\dfrac{1}{2}:3+x=\dfrac{14}{5}\\ \Leftrightarrow x+\dfrac{1}{6}=\dfrac{14}{5}\\ \Leftrightarrow x=\dfrac{79}{30}\\ b,\dfrac{8}{5}:x:\dfrac{7}{4}=\dfrac{11}{6}\\ \Leftrightarrow x=\dfrac{192}{385}\\ c,\dfrac{24}{10}+x:\dfrac{3}{4}=\dfrac{11}{3}\\ \Leftrightarrow\dfrac{4}{3}x=\dfrac{19}{15}\\ \Leftrightarrow x=\dfrac{19}{20}\)

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sai đúng thằng lớp 1

\(\Leftrightarrow\dfrac{5}{4}\left(\dfrac{4}{3\cdot7}+\dfrac{4}{7\cdot11}+...+\dfrac{4}{x\left(x+4\right)}\right)=\dfrac{50}{123}\)

=>(1/3-1/7+1/7-1/11+...+1/x-1/x+4)=50/123:5/4=50/123*4/5=40/123

=>1/3-1/x+4=40/123

=>1/x+4=1/123

=>x+4=123

=>x=119

`a) 3-5+(-x+3)=6`

`=>5+(-x+3)=3-6`

`=>5+(-x+3)=-3`

`=>-x+3=-3-5`

`=>-x+3=-8`

`=>-x=-8-3`

`=>-x=-11`

`=>x=11`

__

`b)(-4-x)+(4-15)=-15`

`=>(-4-x)+-11=-15`

`=>-4-x=-15-(-11)`

`=>-4-x=-15+11`

`=>-4-x=-4`

`=>x=-4-(-4)`

`=>x=-4+4`

`=>x=0`

`c)(11+x)-(-11-9)=32`

`=>(11+x)-(-20)=32`

`=>(11+x)+20=32`

`=>11+x=32-20`

`=>11+x=12`

`=>x=12-11`

`=>x=1`

`a)3-5+(-x+3)=6`

`5+(-x+3)=3-6`

`5+(-x+3)=-3`

`-x+3=-3-5`

`-x+3=-8`

`-x=-8-3`

`-x=-11`

`x=11`

`b,(-4-x)+(4-15)=-15`

`(-4-x)+(-11)=-15`

`-4-x=-15-(-11)`

`-4-x=-15+11`

`-4-x=-4`

`x=-4-(-4)`

`x=-4+4`

`x=0`

`c)(11+x)-(-11-9)=32`

`(11+x)-(-20)=32`

`(11+x)+20=32`

`11+x=32-20`

`11+x=12`

`x=12-11`

`x=1`

Bài 1:

a: \(x=\dfrac{2}{3}:\dfrac{3}{5}=\dfrac{2}{3}\cdot\dfrac{5}{3}=\dfrac{10}{9}\)

b: \(x=\dfrac{17}{8}:\dfrac{7}{17}=\dfrac{17}{8}\cdot\dfrac{17}{7}=\dfrac{289}{56}\)

c: \(x=-\dfrac{3}{4}:\dfrac{7}{12}=\dfrac{-3}{4}\cdot\dfrac{12}{7}=\dfrac{-63}{28}=-\dfrac{9}{4}\)

d: \(\Leftrightarrow x\cdot\dfrac{1}{6}=\dfrac{3}{8}-\dfrac{1}{4}=\dfrac{1}{4}\)

hay \(x=\dfrac{1}{4}:\dfrac{1}{6}=\dfrac{3}{2}\)

e: \(\Leftrightarrow\dfrac{1}{2}:x=-4-\dfrac{1}{3}=-\dfrac{17}{3}\)

hay \(x=-\dfrac{1}{2}:\dfrac{17}{3}=\dfrac{-3}{34}\)

dad

Câu 8:

  x=1/5

Câu 9

a: 2

b:41/36

thực hành ra luôn mọi người

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

Bạn chia từng bài ra được chứ?

a: \(x+\frac45=\frac32\)

=>\(x=\frac32-\frac45=\frac{15}{10}-\frac{8}{10}=\frac{7}{10}\)

b: \(x-\frac32=\frac{11}{4}\)

=>\(x=\frac{11}{4}+\frac32\)

=>\(x=\frac{11}{4}+\frac64=\frac{17}{4}\)

c: \(\frac{25}{3}-x=\frac56\)

=>\(x=\frac{25}{3}-\frac56=\frac{50}{6}-\frac56=\frac{45}{6}=\frac{15}{2}\)

\(\frac{4}{5}\cdot\frac{3}{x}\cdot\frac{2}{11}=\frac{24}{165}\)

        \(\frac{3}{x}\)     \(=\frac{24}{165}:\frac{2}{11}:\frac{4}{5}\)

        \(\frac{3}{x}\)     \(=1\)

         \(x\)     \(=3\)

\(\frac{4}{3}:\frac{x}{5}=\frac{5}{13}\cdot\frac{4}{9}\)

\(\frac{4}{3}:\frac{x}{5}=\frac{20}{117}\)

      \(\frac{x}{5}=\frac{4}{3}:\frac{20}{117}\)

     \(\frac{x}{5}=\frac{39}{5}\)

     \(x=39\)