r1 : { x = -4 - t y = 2 + 2t z = 2t e r2 : { y = 5 - 2x z = 8 - 2x

r1 : rac{x - 2}{4} = rac{y + 1}{-4} = rac{z - 1}{-1} e r2 : { x = t y = 2 + t z = 1 + 3t

r1 : { x = 4 - 5z y = 2 e r2 : rac{x + 3}{-2} = rac{y - 3}{1} = rac{z - 4}{3}

r1 : { x = -1 - 3t y = -3 + 5t z = 3 + 2t e r2 : rac{x + 4}{6} = rac{y - 2}{-10} = rac{z - 5}{-4}