Find `a`, for which the points `A(3, 2, 1), B(4, a, 5), C(4, 2, -2)` and `D(6, 5, -1)` are coplanar.

Find x such that the four points A(3, 2, 1), B(4, x, 5), C(4, 2, -2) and D(6, 5, -1) are coplanar.

Find lambda for which the points A(3,2,1),B(4,lambda,5),C(4,2,-2) and D(6,5,-1) are coplanar.

Find lambda for which the points A(3,\ 2,\ 1),\ B(4,\ lambda,\ 5),\ C(4,\ 2,\ -2)\ a n d\ D(6,\ 5,\ -1) are coplanar.

Show that the points A(3,2,1),B(4,5,5),C(4,2,-2) and D(6,5,-1) are coplanar.

Find x such that the four points A(3,2,1), B(4,x,5), C(4,2,-2) and D (6,5,-1) are coplanar .

Find x such that the four points A(3,2,1), B(4,x,5), C(4,2,-2) and D(6,5,-1) are coplanar

Find x such that the four point A(3,2,1),B(4,x,5),C(4,2,-2) and D(6,5,-1) are coplanar.