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.