A matrix A and an echelon form of A are shown below. Find a basis for Col A and a basis for Nul A. A = Find a basis for Col A. 3 6 12-15 7 15 31-42 3 8 18-29 - 16 3 6 15 2 3 7 3 8 (Simplify your answer. Use a comma to separate answers as needed.) Find a basis for Nul A. 33 137-12 013-7 0 0 0 0 *** (Simplify your answer. Use a comma to separate answers as needed.)