Show that the lines
`(x-1)/(1) = (y-2)/(-1) = (z-1)/(1)` and `(x-1)/(1-) = (y-1)/(-1) = (z-1)/(2)` do not intersect.

Show that the lines (x-1)/(2)=(y-2)/(y-1)=(z-3)/(4) and (x-4)/(5)=(y-1)/(2)=z intersect

Show that the lines (x-4)/(1) = (y+3)/(-4) = (z+1)/(7) and (x-1)/(2) = (y+1)/(-3) = (z+10)/(8) intersect. Also find the co-ordinates of their point of intersection.

Show that the lines (x-1)/(3)=(y+1)/(2)=(z-1)/(5) " and " (x-2)/(2)=(y-1)/(3)=(z+1)/(-2) do not intersect each other .

Show that the lines ( x+1)/(-10) = ( y + 3)/(-1) = ( z - 4) / (1) "and" (x + 10)/(-1) = ( y+1)/(-3) = (z -1)/(4) intersect each other and find the coordinates of the points of intersection .

Show that the lines (x-1)/1 = (y-1)/(-2)=(z-1)/1 and (x-2)/5 = (y+1)/1 = (z-2)/(-6) are coplanar.

Show that the lines (x-1)/1 = (y-1)/(-2)=(z-1)/1 and (x-2)/5 = (y+1)/1 = (z-2)/(-6) are coplanar.

Show that the lines (x-1)/(3)=(y+1)/(2)=(z-1)/(5) and (x+2)/(4)=(y-1)/(3)=(z+1)/(-2) do not intersect.

Show that the lines (x-1)/(3)=(y+1)/(2)=(z-1)/(5) and (x+2)/(4)=(y-1)/(3)=(z+1)/(-2) do not intersect.