Let: v = the matrix: -20 -15 11 18 Write v as a linear combination of the vectors in the following basis of R4: B = 15 9 1 1 9 2 -3 -1 -5 -1 2 1 -11 -5 1 0 (These are four vertical 4x1's, separated by commas.) It is not necessary to verify that B is a basis.

Let u = (1,3, 5) and v = (-4,3, –7) be vectors in R3. (a) Find u + v. (b) Express u in terms of the standard basis vectors in R3. (c) Find -3u.

Find the representation of (9, -2, -3) in each of the following ordered bases. Your answers should be vectors of the general form . a. Represent the vector (9, -2, -3) in terms of the ordered basis B = {i,j,k}. [(9,-2,-3)]B= b. Represent the vector (9, -2, -3) in terms of the ordered basis C = {3, e1, e2}. [(9,-2,-3)] c = c. Represent the vector (9, -2, -3) in terms of the ordered basis D= {-2, -1, e3}. [(9,-2,-3)]D =