Question

Tìm x,y : |x-y+2|+|2y+1|<hoặc=0              

Answer 1

\(\left|x-y+2\right|+\left|2y+1\right|\le0\)

Th1 : \(\hept{\begin{cases}x-y+2>0\\2y+1< 0\end{cases}\Rightarrow\hept{\begin{cases}x-y>-2\\2y< -1\end{cases}\Rightarrow}\hept{\begin{cases}x-y>-2\\y< \frac{-1}{2}\end{cases}}}\)

Th2 : \(\hept{\begin{cases}x-y+2< 0\\2y+1>0\end{cases}\Rightarrow\hept{\begin{cases}x-y< -2\\2y>-1\end{cases}\Rightarrow}\hept{\begin{cases}x-y< -2\\y>-\frac{1}{2}\end{cases}}}\)