Find the value of `x` if the points `(x,-1)(5,7) and (8,11)` are collinear.

Find x if the points (2,-5), (-4,5) and (x,15) are collinear.

Find the value of x for which the points (x, -1), (2, 1) and (4, 5) are collinear.

Find the value of a+b, if the points (2,a,3),(3,-5,b) and (-1,11,9) are collinear.

Find the unknown x if the points (2,4), (7,x) and (-1,1) are collinear.

By using determinants, find the value of 'y' for which the points (1,3),(2,5) and (3,y) are collinear.

Find x and y if the point (x,-1,3), (3,y,1) and (-1,11,9) are collinear. Also, write down the vector equation of the line in which they lie. Further, find the point of intersection of this line and the plane x+y+z+1=0 .

The value of x such that the points (8,1),(x,-4) and (2,-5) are collinear is:

Find the values of x and y if the points (x,-1,3), (3,y,1) and (-1, 11,9) are collinear.

Determine if the points (1, 5), (2, 3) and (- 2,- 11) are collinear.