Problem #6: Suppose that A, B, and C are 72 x 72 matrices that satisfy the following equation, [2 marks] (A + 5BC-]) 1 = 40. Find an expression for A , assuming that all of the relevant matrices are invertible. (A) C(1 -5B) (B) C(41 -5B) (C) C(4-5B) 1 (D) (1 -5B) C (E) (4-5B) 'C (F) (41-5B) 'C (G) 4C-CB (H) (41-5B) C ()C(HI-5B) Problem #6: Select v Save Problem #7: A matrix A is called self-inverse if A" = A. Which of the following statements are always true? [2 marks] (i) If A is self-inverse then KA is also self-inverse where k is any nonzero constant. (1i) If A is self-inverse then A' is also self-inverse. (iii) If A and B are both self-inverse 97 x 97 matrices, then the matrix AB is also self-inverse. (A) (i) and (iii) only (B) (i) only (C) none of them (D) (iii) only (E) (i) and (ii) only (F) (ii) and (iii) only (G) all of them (H) (ii) only Problem #7: Select v