Suppose that T (R; R') for some n, m N. a) Find the matrix representative

Question:

Suppose that T ∈ £(R"; R'") for some n, m ∈ N.
a) Find the matrix representative of T if T(x, y, z, w) = (0, x + y, x - z, x + y + w).
b) Find the matrix representative of T if T(x, y, z) = x - y + z.
c) Find the matrix representative of T if T(x1, x2,..., xn) = (x1 - xn, xn - x1).