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X + 1/5 = 9/15

X = 9/15 - 1/5

X = 2/5

`x + 3/5 xx 1/3 = 9/15`

`x + 1/5 = 9/15`

`x = 9/15 - 1/5`

`x = 6/15`

2/5x1/4:3/2

=2/20 : 3/2

=4/60=1/15

=>2/35<x<8/3

hay \(x\in\left\{1;2\right\}\)

2/5 x 1/4 : 3/8

=1/10 : 3/8

=4/15

2/5*1/4:3/8

=3/20:3/8

=3/20*8/3

=8/20

=2/5

Ai tích mk mk tích lại

\(\dfrac{11}{3}-\dfrac{2}{3}\left(2\dfrac{2}{5}x\dfrac{1}{4}+0,2\right)\)

\(\Leftrightarrow3\left(\dfrac{12}{5}\times\dfrac{1}{4}+0,2\right)\)

\(\Leftrightarrow3\left(\dfrac{3}{5}+\dfrac{1}{5}\right)\)

\(\Leftrightarrow3\times\dfrac{4}{5}\)

\(\Leftrightarrow\dfrac{12}{5}\)

`1/5xx1/2:3/10`

`=1/10xx10/3`

`=1/3`

`1/2xx1/3:1/4`

`=1/6xx4/1`

`=2/3`

a) \(\dfrac{1}{5}\times\dfrac{1}{2}:\dfrac{3}{10}=\dfrac{1}{5}\times\dfrac{1}{2}\times\dfrac{10}{3}=\dfrac{1\times1\times10}{5\times2\times3}=\dfrac{10}{30}=\dfrac{1}{3}\)

b) \(\dfrac{1}{2}\times\dfrac{1}{3}:\dfrac{1}{4}=\dfrac{1}{2}\times\dfrac{1}{3}\times4=\dfrac{1\times1\times4}{2\times3}=\dfrac{4}{6}=\dfrac{2}{3}\)

\(\frac{7}{9}\times\frac{3}{5}+\frac{3}{5}\times\frac{5}{6}+\frac{3}{5}\times1\)

\(=\frac{3}{5}\times\left(\frac{7}{9}+\frac{5}{6}+1\right)\)

\(=\frac{3}{5}\times\frac{47}{18}\)

\(=\frac{47}{30}\)

 #hoktot<3# 

\(\frac{x}{5}\times\frac{1}{3}=\frac{2}{15}\)

\(\frac{x}{5}=\frac{2}{15}:\frac{1}{3}\)

\(\frac{x}{5}=\frac{2}{5}\)

\(\Rightarrow x=2\)

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