If A= [ array ll 2 & 7 1 & 5 array ] then that is A+3 A⁻¹ equal to? where I is the identity matrix order 2 .

Step-by-step solution

A= [ array ll 2 & 7 1 & 5 array ] Now, A⁻¹= 1 | ~A | adj ( A ) aligned & = 1 (10-7) [ array cc 5 & -7 -1 & 2 array ] & = 1 3 [ array cc 5 & -7 -1 & 2 array ] aligned aligned & 3 ~A ⁻¹= [ array cc 5 & -7 -1 & 2 array ] & Now, A+3 ~A ⁻¹= [ array ll 2 & 7 1 & 5 array ]+ [ array cc 5 & -7 -1 & 2 array ] & = [ array ll 7 & 0 0 & 7 array ]=7 [ array ll 1 & 0 0 & 1 array ]=7 I where I is Identity Matrix. aligned