4. Let 1 1 A- [1 4] 1. (1 mark) Find A'1 by using the formula an 112 _ 1 622 tm . A = => A 1 = Wlth (111(122 {112(121 7E 0 \"21 9'22 (111E122 {112921 G21 11111 2. Rowreduce l 1 1 0 [Alf] _ [1 1 i 0 1] Perform the following Operation on [AH] o (2 marks) Keep R1 and substitute R2 > R2 + R1 0 (2 marks) Keep R2 and substitute R1 > 2R1 + R2 0 (2 marks) substitute R1 > %R1, and substitute R2 > %R2, 3. (1 mark) Find A'1