Answer
(1, 4, -5)
(3, -7, 4) 2 x 3 Matrix
Work Step by Step
Because e1 e2 and e3 are all the columns of a 3 x 3 identity matrix, that means that the A = the identity matrix.
Therefore, you need a 3x2 matrix to multiply A by the standard matrix. A x (Matrix above). You get the values of the standard matrix by looking at T(e1), T(e2), T(e3).