so I have a question I cannot answer in my calculus/vectors course, and it's driving me insane. if someone could just tell me how to findki would be forever grateful.

'Find the value ofksuch that the three planes will always intersect in a point, then find the point of intersection.'

π1: x+2y-z-5=0

π2: x+ky-3z+11=0

π3 2x+y+z+10=0