Show that each one of the following systems of linear equations is inconsistent

4x – 5y – 2z = 2


5x – 4y + 2z = – 2


2x + 2y + 8z = – 1


|A| = 4(– 36) + 5(36) – 2(18)


|A| = 0


Cofactors of A are:


C11 = (– 1)1 + 1 – 32 – 4 = – 36


C21 = (– 1)2 + 1 – 40 + 4 = – 36


C31 = (– 1)3 + 1 – 10 – 8 = – 18


C12 = (– 1)1 + 2 40 – 4 = – 36


C22 = (– 1)2 + 1 32 + 4 = 36


C32 = (– 1)3 + 1 8 + 10 = – 18


C13 = (– 1)1 + 2 10 + 8 = 18


C23 = (– 1)2 + 1 8 + 10 = – 18


C33 = (– 1)3 + 1 – 16 + 25 = 9


adj A =


=


Adj A x B =


=


Hence, The above system is inconsistent.


4