What is the value of y so that the line through (3,y) and (4,9) is parallel to the line through (-1,6) and (0,8)?

What is the value of y so that the line through (3,y)a n d(2,7) is parallel to the line through (-1,4)a n d(0,6)?

Show that the line : through (0, 0) and (2, 3) is parallel to the line through (2, 2) and (4, 5) .

Show that the line : through (- 2, 6) and (4, 8) is perpendicular to the line through (8, 12) and (4, 24).

Show that the line through the points : (4,7,8), (2,3,4) is parallel to the line through the points (-1,-2,1) and (1,2,5).

Find the equation of the lines through (- 2, -1) and are : parallel to line x = 0.

Show that the line through the points (4, 7, 8), (2, 3, 4) is parallel to the line through the points (– 1, – 2, 1), (1, 2, 5).

Find the vector and cartesion equation of the line through the point (3,0,3) and is parallel to the line (x-2)/(3)=(y+1)/(1)=(z-7)/(9) .

Prove that the line through A(0,-1,-1) and B(4,5,1) intersects the line through C(3,9,4) and D(-4,4,4). Also find their point of intersection.