11. Let A be a 3 x 5 matrix. a. Give all the possible values for the rank of A. b. If the Rank of A is 3, what are the dimensions of its column space? C. If the rank of A is 3, what are the dimension of the solution space of the homogeneous system Ax=0? a Obl 12. Let W be the set of all 3 x 3 matrices of the form oc show that W is a subspace of Ld 0 e M33. 13. Show that every vector in R of the form fort any real numbers, is a null space of the 1 2 11 matrix A = -1 0 11 1264 14. Which of the following given subsets of R are subspaces. The set of all vectors of the form filio a. b b. La + 2b) - 0 : d. b], where a +2b-c = 0. 15. If A is a nonsingular matrix, what is the null space of A