故 A 167-1 12 (4)A 0031 0 4=24A1=A3=A1=Ax2=A12=A13=0 A,,=24 A,,=12 10 120 A12=(-1)230=-12413=(-1)210=-12 120 100 (-15213=3 A2x=(-1)°2 121 00 00 4 13=-5 7120=-2 1 2 0 故A 8-I.-I乙 000 63 2412 (5)4=1≠0故A存在 而 AAA A21=-2A31=0 2A,=5A2,=0A,=0 0A,,=0A2,=2 A14=0A24=0A34=-544=82 故 −  = A A A 1 1           − − − − − = 16 7 1 2 1 3 2 13 2 1 0 (4)               = 1 2 1 4 2 1 3 0 1 2 0 0 1 0 0 0 A A = 24 A21 = A31 = A41 = A32 = A42 = A43 = 0 A11 = 24 A22 = 12 A33 = 8 A44 = 6 12 1 1 4 2 3 0 1 0 0 ( 1) 3 A12 = − = − 12 1 2 4 2 1 0 1 2 0 ( 1) 4 A13 = − = − 3 1 2 1 2 1 3 1 2 0 ( 1) 5 A14 = − = 4 1 2 4 2 1 0 1 0 0 ( 1) 5 A23 = − = − 5 1 2 1 2 1 3 1 0 0 ( 1) 6 A24 = − = − 2 1 2 1 1 2 0 1 0 0 ( 1) 7 A34 = − = − −  = A A A 1 1 故                   − − − − − = − 4 1 12 1 24 5 8 1 0 3 1 6 1 2 1 0 0 2 1 2 1 1 0 0 0 1 A (5) A = 1  0 故 −1 A 存在 而 A11 = 1 A21 = −2 A31 = 0 A41 = 0 A12 = −2 A22 = 5 A32 = 0 A42 = 0 A13 = 0 A23 = 0 A33 = 2 A43 = −3 A14 = 0 A24 = 0 A34 = −5 A44 = 8