write u as Linear Combination of vectors - Linear Algebra

1. Determine if the vector v = (−2, −3, 1) is in
span{(1,1,1),(1,−1,5),(2,1,4),(−1,−3,3)}. (Answer:NO).
2. Write u = (−1,1,−1) as a linear combination of v1 = (1,2,1), v2 = (−2,1,0) and
v3 =(1,1,1).
(Answer:u = 2v1 − 0v2 − 3v3).