Solve y=x/x+aquad[x]

$$y = \frac { x } { x + a } \quad [ x ]$$

Solve for x (complex solution)

$$\left\{\begin{matrix}x=\frac{\sqrt{y\left(y+4a\right)}+y}{2}\text{, }&\left(arg(y)<\pi \text{ and }y\neq 0\right)\text{ or }a\neq 0\\x=\frac{-\sqrt{y\left(y+4a\right)}+y}{2}\text{, }&\left(arg(y)\geq \pi \text{ and }y\neq 0\right)\text{ or }a\neq 0\end{matrix}\right.$$

Solve for a

$$\left\{\begin{matrix}a=\frac{x\left(x-y\right)}{y}\text{, }&x\neq 0\text{ and }y\neq 0\\a\neq 0\text{, }&y=0\text{ and }x=0\end{matrix}\right.$$

Solve for x

$$\left\{\begin{matrix}x=\frac{\sqrt{y\left(y+4a\right)}+y}{2}\text{, }&\left(y\leq -4a\text{ or }y\geq 0\right)\text{ and }\left(y>0\text{ or }a\neq 0\right)\text{ and }\left(y\leq 0\text{ or }y\geq -4a\right)\text{ and }\left(y\geq 0\text{ or }a\neq 0\right)\\x=\frac{-\sqrt{y\left(y+4a\right)}+y}{2}\text{, }&\left(y<0\text{ and }y\leq -4a\right)\text{ or }\left(a\neq 0\text{ and }y=-4a\right)\text{ or }\left(a\neq 0\text{ and }y\leq -4a\text{ and }y\leq 0\right)\text{ or }\left(a\neq 0\text{ and }y\geq 0\text{ and }y\geq -4a\right)\end{matrix}\right.$$