求解 {l}{x+y^2+2=0}{z=x+y}{text{Solvefor}atext{where}}{a=z}

$$\left. \begin{array} { l } { x + y ^ {2} + 2 = 0 }\\ { z = x + y }\\ { \text{Solve for } a \text{ where} } \\ { a = z } \end{array} \right.$$

求解 x, y, z 的值 (复数求解)

$$x=a+\frac{\sqrt{-4a-7}}{2}-\frac{1}{2}\text{, }y=\frac{-\sqrt{-4a-7}+1}{2}\text{, }z=a$$

$$x=a-\frac{\sqrt{-4a-7}}{2}-\frac{1}{2}\text{, }y=\frac{\sqrt{-4a-7}+1}{2}\text{, }z=a$$

求解 x, y, z 的值

$$x=a+\frac{\sqrt{-4a-7}}{2}-\frac{1}{2}\text{, }y=\frac{-\sqrt{-4a-7}+1}{2}\text{, }z=a$$

$$x=a-\frac{\sqrt{-4a-7}}{2}-\frac{1}{2}\text{, }y=\frac{\sqrt{-4a-7}+1}{2}\text{, }z=a\text{, }a\leq -\frac{7}{4}$$