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ta thay 13 chia het cho 13 và cũng ngược lại 13 cũng chia hết cho 13
Ta lập thành phép tính (x-2)=13
Suy ra: x=13+2=15
Vậy x bằng 15 bạn nhé!
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Ta có : \(\frac{-2}{7}< \frac{6}{x}< \frac{3}{-13}\Rightarrow\frac{-6}{21}< \frac{-6}{-x}< \frac{-6}{26}\Rightarrow21< -x< 26\Rightarrow-x\in\left\{22;23;24;25\right\}\)
=> \(x\in\left\{-22;-23;-24;-25\right\}\)
Ta có
\(-\frac{2}{7}< \frac{6}{x}< \frac{3}{-13}\)
\(\Rightarrow\frac{-6}{21}< \frac{-6}{-x}< \frac{-6}{26}\)
\(\Leftrightarrow21< -x< 26\)
\(\Rightarrow-x\in\left\{22;23;24;25\right\}\)
hay \(x\in\left\{-22;-23;-24;-25\right\}\)
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(-9)2 . X = 150 + 12 . 13 . X
=> 81x=150+156x
=> 81x-156x=150
=>-75x=150
=> x=-2
#kenz
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\(a,x+y=xy\)
\(\Rightarrow x-xy+y-1=-1\)
\(\Rightarrow x\left(1-y\right)-\left(1-y\right)=-1\)
\(\Rightarrow\left(x-1\right)\left(1-y\right)=-1\)
TH1 : \(\hept{\begin{cases}x-1=1\\1-y=-1\end{cases}\Rightarrow\hept{\begin{cases}x=2\\y=2\end{cases}}}\)
TH2 : \(\hept{\begin{cases}x-1=-1\\1-y=1\end{cases}\Rightarrow\hept{\begin{cases}x=0\\y=0\end{cases}}}\)
\(b,xy-x+2\left(y-1\right)=13\)
\(\Rightarrow x\left(y-1\right)+2\left(y-1\right)=13\)
\(\Rightarrow\left(x+2\right)\left(y-1\right)=13\)
TH1 : \(\hept{\begin{cases}x+2=1\\y-1=13\end{cases}\Rightarrow\hept{\begin{cases}x=-1\\y=14\end{cases}}}\)
TH2 : \(\hept{\begin{cases}x+2=13\\y-1=1\end{cases}\Rightarrow\hept{\begin{cases}x=11\\y=2\end{cases}}}\)
TH3 : \(\hept{\begin{cases}x+2=-1\\y-1=-13\end{cases}\Rightarrow\hept{\begin{cases}x=-3\\y=-12\end{cases}}}\)
TH4 : \(\hept{\begin{cases}x+2=-13\\y-1=-1\end{cases}\Rightarrow\hept{\begin{cases}x=-15\\y=0\end{cases}}}\)