Need help with these

h 18. Let v1 = 2 U2 and v3 - 3 .Determine the value(s) of h so that N {21, 12, v3} is a linearly dependent set. Justify your answer. 19. Determine by inspection whether the given vectors are linearly independent. Justify your answers. a 3 b. 20. Mark each question as true or false. Justify each answer. a. The columns of a matrix A are linearly independent if the equation Ax - 0 has the trivial solution. b. If u, v E R4 and w is a linearly combination of u and v, then {u, v, w} is linearly dependent. c. If a set in R' is linearly dependent, then it contains more than 5 vectors. d. The columns of a 4 x 5 matrix are linearly dependent. 2 3 5 -3 21. Let A = Observe that the third column of A is the sum of the first two -2 do 1 2 columns of A. Without doing any calculations, use this information to find a nontrivial solution to Ax = 0