- $ \\\frac{x}{2} = \\\frac{{y + 1}}{1} = \\\frac{{z - 3}}{1}$.
- $ \\\frac{{x - 1}}{{ - 2}} = \\\frac{y}{1} = \\\frac{{z - 1}}{1}$
- $ \\\frac{x}{{ - 2}} = \\\frac{{y + 1}}{1} = \\\frac{{z - 3}}{1}$.
- $ \\\frac{{x - 1}}{{ - 2}} = \\\frac{y}{1} = \\\frac{{z - 1}}{{ - 1}}$