If ( A= [ array cc 3 & 1 -1 & 2 array ] ) then ( A²-5 A ) is equal to

Step-by-step solution

Given that, ( A= [ array cc 3 & 1 -1 & 2 array ] ) So, ( A²= [ array cc 3 & 1 -1 & 2 array ] [ array cc 3 & 1 -1 & 2 array ] ) ( = [ array cc 9-1 & 3+2 -3-2 & -1+4 array ]= [ array cc 8 & 5 -5 & 3 array ] ) And ( 5 A=5 [ array cc 3 & 1 -1 & 2 array ]= [ array cc 15 & 5 -5 & 10 array ] ) Therefore, [ array l A²-5 A= [ array cc 8 & 5 -5 & 3 array ]- [ array cc 15 & 5 -5 & 10 array ] = [ array cc -7 & 0 0 & -7 array ]=-7 I array ]