$$\frac { 68 } { 21 } = x + \frac { 1 } { y + \frac { 1 } { z } } x , y , z x , y , z$$
$x=\frac{68\left(yz+1\right)}{21\left(yz+z+1\right)}$
$y\neq -1-\frac{1}{z}\text{ and }y\neq -\frac{1}{z}\text{ and }z\neq 0$
$y=-\frac{21xz+21x-68}{z\left(21x-68\right)}$
$\left(x=\frac{68}{21\left(z+1\right)}\text{ or }x\neq 0\right)\text{ and }z\neq 0\text{ and }\left(x=\frac{68}{21\left(z+1\right)}\text{ or }x\neq \frac{68}{21}\right)\text{ and }\left(z\neq -1\text{ or }x\neq 0\right)\text{ and }\left(x\neq \frac{68}{21}\text{ or }z\neq -1\right)$
