Let A = B =

So, AX = B

Or, X = A ^{– 1}B

|A| = 1

Cofactors of A are

C₁₁ = 1 C₁₂ = – 1

C₂₁ = – 4 C₂₂ = 5

Since, adj A =

(adj A) =

=

Now, A ^{– 1} =

A ^{– 1} =

So, X =

Hence, X =