`ahati + ahatj + chatk , hati+hatk , chati + chatj + bhatk` are coplaner vector then find the relation between `a,b,c` and find value of c

Vectors 5hati+yhatj+hatk,2hati+2hatj-2hatk and -hati+2hatj+2hatk are coplaner then find the value of y.

Vectors 2hati+2hatj-2hatk,5hati+yhatj+hatk and -hati+2hatj+2hatk are coplanar then find the value of y.

If the vectors 2ahati+bhatj+chatk, bhati+chatj+2ahatk and chati+2ahatj+bhatk are coplanar vectors, then the straight lines ax+by+c=0 will always pass through the point

If veca = hati - hatj + hatk, vecb= 2 hati + hatj -hatk and vec c = lamda hati -hatj+ lamda hatk are coplanar, find the value of lamda.

If hat(i) + hatj + hatk, 2 hati + 5 hatj , 3 hati + 2 hatj - 3 hatk and hati - 6 hatj - hatk respectively are the position vectors of points A, B , C and D, then find the angle between the straight lines AB and CD. Find whether bar(AB) and bar(CD) are collinear or not.

The position vectors of the point A, B, C and D are 3hati-2hatj -hatk, 2hati+3hatj-4hatk, -hati+hatj+2hatk and 4hati+5hatj +lamda hatk , respectively. If the points A, B, C and D lie on a plane, find the value of lamda .