Show that each of the following systems of linear equations is consistent and also find their

Solution:


2x + 2y – 2z = 1


4x + 4y – z = 2


6x + 6y + 2z = 3


|A| = 2(14) – 2(14) – 2(0)


|A| = 0


So, A is singular. Thus, the given system is either inconsistent or it is consistent with infinitely many solution according to as:


(Adj A)x B≠0 or (Adj A)x B = 0


Cofactors of A are:


C11 = (– 1)1 + 18 + 6 = 14


C21 = (– 1)2 + 1 4 + 12 = – 16


C31 = (– 1)3 + 1 – 2 + 8 = 6


C12 = (– 1)1 + 2 8 + 6 = – 14


C22 = (– 1)2 + 1 4 + 12 = 16


C32 = (– 1)3 + 1 – 2 + 8 = – 6


C13 = (– 1)1 + 2 24 – 24 = 0


C23 = (– 1)2 + 1 12 – 12 = 0


C33 = (– 1)3 + 1 8 – 8 = 0


adj A =


=


Adj A x B =


Now, AX = B has infinite many solution


Let z = k


Then, 2x + 2y = 1 + 2k


4x + 4y = 2 + k


This can be written as:



Hence, |A| = 0 z = 0


Hence, The given equation doesn’t satisfy .


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