\(\dfrac{-9}{7}+\dfrac{5}{-7}< x\le\dfrac{-5}{2}+\dfrac{18}{4}\)

\(\dfrac{-9}{7}+\dfrac{-5}{7}< x\le\dfrac{10}{4}+\dfrac{18}{4}\)

\(\dfrac{-14}{7}< x\le2\)

\(-2< x\le2\)

\(\Rightarrow\)\(x=\left\{-1;0;1;2\right\}\)

-2<-1,0,1,2<2

\(\left\{\dfrac{-5< 0< -0,4}{x\in Z}\right\}\Rightarrow x\in\left\{-4;-3;-2;-1\right\}\)

chiu thôi leo nheo qua

chịu không viết được hỗn số

nó phải có = bao nhiêu thì mới ra kết quả bạn ạ 

\(\dfrac{2x-9}{240}\) \(=\) \(\dfrac{39}{80}\) \(\Leftrightarrow\) \(\left(2x-9\right)\) \(.80\) \(=\) \(240.39\)

\(2x\) \(-\) \(9\) \(=\) ( \(240\) \(.\) \(39\) ) \(:\) \(80\)

\(2x\) \(-\) \(9\) \(=\) \(117\)

\(2x\) \(=\) \(126\)

\(x\) \(=\) \(63\) 

$x$ $=$ $63$ 

`(-12)/(9-x) =4/5`

`=> -12.5=(9-x).4`

`=> -60=(9-x).4`

`=> (9-x).4=-60`

`=>9-x=-60:4`

`=>9-x=-15`

`=>x=9-(-15)`

`=>x=9+15`

`=>x= 24`

X=15

\(\dfrac{x}{5}=\dfrac{3}{y}\Rightarrow xy=15\)

\(\Rightarrow x;y\inƯ\left(15\right)=\left\{\pm1;\pm3;\pm5;\pm15\right\}\)

\(\dfrac{x}{5}\)\(=\dfrac{3}{y}\)

\(\Rightarrow\)\(x.y=3.5\)

\(\Rightarrow\)\(x.y=15\)

⇒\(x=\dfrac{15}{y}\)

=>x=5x14:8=70/8=8,75

⇒5.14=8x

⇔70=8x

⇔x=8,75

\(\dfrac{5}{8}=\dfrac{x}{14}\)

⇔ \(8x=70\)

⇒ \(x=\dfrac{35}{4}\)

=>x=70/8=35/4

\(\dfrac{5}{8}=\dfrac{x}{14}\Rightarrow5.14=8.x=70\\ \Rightarrow x=70:8\\ \Rightarrow x=8,75\)

<=> 5.14 = 8x

<=> 70=8x

<=> x=8.75