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

2x + 5y = 7


6x + 15y = 13

The above system of equations can be written as


or AX = B


Where A = B = and X =


|A| = 30 – 30 = 0


So, A is singular,Now X will be consistence if (Adj A)xB = 0


C11 = (– 1)1 + 1 15 = 15


C12 = (– 1)1 + 2 6 = – 6


C21 = (– 1)2 + 1 5 = – 5


C22 = (– 1)2 + 2 2 = 2


Also, adj A =


=


(Adj A).B =


=


= ≠


Hence, The given system is inconsistent.


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