- $ \\\frac{{x + 1}}{3} = \\\frac{{y + 2}}{4} = \\\frac{z}{3}.$
- $ \\\frac{{x - 1}}{3} = \\\frac{{y - 2}}{4} = \\\frac{z}{3}.$
- $ \\\frac{{x + 1}}{1} = \\\frac{{y + 2}}{2} = \\\frac{z}{{ - 1}}.$
- $ \\\frac{{x - 1}}{1} = \\\frac{{y - 2}}{2} = \\\frac{z}{{ - 1}}.$