a)\(-\frac{3}{7}+x=\frac{1}{3}\)

\(x=\frac{1}{3}+\frac{3}{7}\)

\(x=\frac{16}{21}\)

b)\(\frac{3}{4}+\frac{1}{4}:x=\frac{2}{5}\)

\(\frac{1}{4}:x=\frac{2}{5}-\frac{3}{4}\)

\(\frac{1}{4}:x=-\frac{7}{20}\)

\(x=\frac{-7}{20}x\frac{1}{4}\)

\(x=-\frac{7}{80}\)

d)\(\left|x-3\right|=\frac{1}{2}\)

\(\Rightarrow\hept{\begin{cases}x-3=\frac{1}{2}\\x-3=\frac{-1}{2}\end{cases}}\Rightarrow\hept{\begin{cases}x=\frac{7}{2}\\x=\frac{5}{2}\end{cases}}\)

Mk bổ sung nha

c)\(1\frac{1}{3}:0,8=\frac{2}{3}:0,1x\)

\(\frac{5}{3}=\frac{2}{3}:0,1x\)

\(0,1x=\frac{2}{3}:\frac{5}{3}\)

\(0,1x=\frac{2}{5}\)

\(x=\frac{2}{5}:0,1\)

\(x=4\)

2155265bg

\(\dfrac{2}{3}:0.1x=\dfrac{4}{3}:0.8=\dfrac{4}{3}:\dfrac{4}{5}=\dfrac{5}{3}\)

=>0,1x=2/3:5/3=2/5

=>x=1/10:2/5=1/10x5/2=5/20=1/4

\(\dfrac{4}{3}:0,8=\)\(\dfrac{2}{3}:0,1x\)

\(\dfrac{4}{3}:\dfrac{4}{5}=\dfrac{2}{3}\)\(:\dfrac{1}{10}x\)

\(\dfrac{4}{3}.\dfrac{5}{4}=\dfrac{2}{3}:\dfrac{x}{10}\)

\(\dfrac{5}{3}=\dfrac{2}{3}.\dfrac{10}{x}\)

⇒\(\dfrac{10}{x}=\dfrac{5}{3}:\dfrac{2}{3}\)\(=\dfrac{5}{3}.\dfrac{3}{2}\)\(=\dfrac{5}{2}\)

⇒\(\dfrac{10}{x}=\dfrac{5}{2}\)⇒\(x=10:\dfrac{5}{2}=10.\dfrac{2}{5}=\dfrac{20}{5}=4\)

\(1\dfrac{1}{3}:0,8=\dfrac{2}{3}:\left(0,1\right).x\)

\(\Rightarrow\dfrac{4}{3}:\dfrac{4}{5}=\dfrac{2}{3}:\dfrac{1}{10}.x\)

\(\Rightarrow\dfrac{4}{3}.\dfrac{5}{4}=\dfrac{2}{3}.10x\)

\(\Rightarrow\dfrac{5}{3}=\dfrac{2}{3}.10x\)

\(\Rightarrow10x=\dfrac{5}{3}:\dfrac{2}{3}\)

\(\Rightarrow10x=\dfrac{5}{2}\)

\(\Rightarrow x=\dfrac{5}{2}:10=\dfrac{1}{4}\)

Vậy \(x=\dfrac{1}{4}\)

\(1\dfrac{1}{3}:0,8=\dfrac{2}{3}:0,1x\Rightarrow\dfrac{4}{3}:\dfrac{3}{5}=\dfrac{2}{3}:\dfrac{1}{10}x\)

\(\Rightarrow\dfrac{4}{3}.\dfrac{5}{3}=\dfrac{2}{3}.10x\Rightarrow\dfrac{20}{9}=\dfrac{20}{3}x\Rightarrow x=\dfrac{1}{3}\)

Vậy...................................................

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Hứa k r lm cko! Bài dài lắm

( 0,25x ) : 3 = 5/6 : 0,125

( 1/4x ) : 3 = 5/6 : 1/8

( 1/4x ) : 3 = 5/6 x 8

( 1/4x ) : 3 = 20/3

1/4x          = 20/3 x 3

1/4x         = 20

x              = 20 : 1/4

x              = 80

0,01 : 2,5 = ( 0,75x ) : 0,75

1/100 : 25/10 = (3/4x) : 3/4

1/100 x 10/25 = (3/4x) : 3/4

=>(3/4x) : 3/4 = 1/250

3/4x                = 1/250 x 3/4

3/4x                = 3/1000

x                     = 3/1000 : 3/4

x                     = 1/250

 4/3 : 0,8 = 2/3 : ( 0,1x )

<=>2/3 : (0,1x) = 4/3 : 0,8

2/3 : (0,1x) = 4/3 : 4/5

2/3 : (0,1x) = 4/3 x 5/4

2/3 : (0,1x) = 5/3

2/3 : (1/10x) = 5/3

1/10x           = 2/3 : 5/3

1/10x           = 2/3 x 3/5

1/10x           = 2/5

x                  = 2/5 : 1/10

x                  = 2/5 x 10

x                  = 4

a: \(\dfrac{2}{3}:0.1x=\dfrac{4}{3}:\dfrac{4}{5}=\dfrac{4}{3}\cdot\dfrac{5}{4}=\dfrac{5}{3}\)

\(\Leftrightarrow x\cdot\dfrac{1}{10}=\dfrac{2}{3}:\dfrac{5}{3}=\dfrac{2}{5}\)

\(\Leftrightarrow x=\dfrac{2}{5}:\dfrac{1}{10}=\dfrac{2}{5}\cdot10=4\)

b: |x-3|=1/2

=>x-3=1/2 hoặc x-3=-1/2

=>x=7/2 hoặc x=5/2

\(\frac{4}{3}\div0,8=\frac{2}{3}\div0,1\)

\(\frac{5}{3}\ne\frac{20}{3}\)

\(\Rightarrow\frac{4}{3}\div0,8\ne\frac{2}{3}\div0,1\)