... 1 1 −7 − 6 18 −7 − 6 26 cofactors + (-1 -2 ), -( - 1-1 ), +( 2-1 ) -( - 8-1 0), + (-2 -5 ), -( 4-8 ) +( 8-5 ), -( 2-5 ), +( 2-8 ) − 18 A-1 3 = |A | At c = −7 15 − 6 Now x ... 68 − 35 + (-3 5-0 ), -( -3 2-3 6), +( 0-3 5) Ac = − −4 -( - 1-0 ), + (-1 -1 ), -( 0-1 ) +(3 6-3 5), -( 3 6-3 2), +(3 5-3 2) −35 1 At c = 68 − − 4 −35 Now, 3 −35 A-1 1 = |A ... −2 −1 4 −3 17 17 17 8 17 17 - 17 are inverse and B = 10 - - 17 17 17 17 17 17 8 17 17 - 17 10 - - 17 17 17 −2 1 17 0 −9...