{l}{4x-ygeq-4}{x+5yleq20}{x-3yleq21}{2x-yleq7} を解きます| Microsoft 数学ソルバー

$$\left. \begin{array} { l } { 4 x - y \geq - 4 } \\ { x + 5 y \leq 20 } \\ { x - 3 y \leq 21 } \\ { 2 x - y \leq 7 } \end{array} \right.$$

x を解く

$$\left\{\begin{matrix}x=3y+21\text{, }&y=-8\\x\in \begin{bmatrix}\frac{y}{4}-1,\frac{y+7}{2}\end{bmatrix}\text{, }&\left(y>-7\text{ and }y<-\frac{1}{8}\right)\text{ or }\left(y\geq -\frac{1}{8}\text{ and }y<3\right)\\x\in \begin{bmatrix}\frac{y}{4}-1,20-5y\end{bmatrix}\text{, }&y\geq 3\text{ and }y\leq 4\\x\in \begin{bmatrix}\frac{y}{4}-1,3y+21\end{bmatrix}\text{, }&y>-8\text{ and }y\leq -7\end{matrix}\right.$$

y を解く

$$\left\{\begin{matrix}y\in \begin{bmatrix}\frac{x}{3}-7,4x+4\end{bmatrix}\text{, }&x\geq -3\text{ and }x<0\\y=-\frac{x}{5}+4\text{, }&x=5\\y\in \begin{bmatrix}2x-7,-\frac{x}{5}+4\end{bmatrix}\text{, }&x>0\text{ and }x<5\\y\in \begin{bmatrix}\frac{x}{3}-7,-\frac{x}{5}+4\end{bmatrix}\text{, }&x=0\end{matrix}\right.$$