I'm having trouble trying to solve this question.. The question states "Let S={r,u,d,x} be a set of vectors.

If x=4r+4u+4d, determine whether or not the four vectors listed above are linearly independent or linearly dependent. If is dependent, find a non-trivial linear relation. I don't get how to get started. I know that a linear indepedant relationship is if the scalars are all 0 and a linear dependent relationship is when atleast one ore more of the scalars or weights are nonzero.