Đáp án:
Giải thích các bước giải:
\(\left(2x+1\right)\left(y-5\right)=10\)
Vì \(x,y\in N\Leftrightarrow2x+1\in N,y-5\in N;2x+1,y-5\inƯ\left(10\right)\)
\(\Leftrightarrow\left[{}\begin{matrix}\left\{{}\begin{matrix}2x+1=10\\y-5=1\end{matrix}\right.\\\left\{{}\begin{matrix}2x+1=1\\y-5=10\end{matrix}\right.\\\left\{{}\begin{matrix}2x+1=5\\y-5=2\end{matrix}\right.\\\left\{{}\begin{matrix}2x+1=2\\y-5=5\end{matrix}\right.\end{matrix}\right.\) \(\Leftrightarrow\left[{}\begin{matrix}\left\{{}\begin{matrix}x=\dfrac{9}{2}\left(loại\right)\\y=6\end{matrix}\right.\\\left\{{}\begin{matrix}x=0\\y=15\end{matrix}\right.\\\left\{{}\begin{matrix}x=2\\y=7\end{matrix}\right.\\\left\{{}\begin{matrix}x=\dfrac{1}{2}\left(loại\right)\\y=10\end{matrix}\right.\end{matrix}\right.\)
`(3x+1)(y-2)=36`
`Th1`
`(3x+1)=36`
`3x=36-1`
`3x=35`
`x=35:3`
`x=35/3`
`Th2`
`(y-2)=36`
`y=36+2`
`y=38`
vậy `x,y ∈ (35/3;38)`
