$\left\{\begin{matrix}x=\frac{2\left(28y+33\right)}{3\left(4y+15\right)}\text{, }y\in \mathrm{R}\setminus -\frac{15}{4},-\frac{3}{4}\text{, }z=-\frac{35}{4}=-8.75\text{, }&b=-45\\x=\frac{2\left(28y+33\right)}{3\left(4y+15\right)}\text{, }y\in \mathrm{R}\setminus -\frac{15}{4},-\frac{3}{4}\text{, }z=-\frac{-4by+240y-15b-360}{12\left(4y+3\right)}\text{, }&b\neq -45\end{matrix}\right.$