Solve the following system of equations by matrix method:
5x + 2y = 3
3x + 2y = 5
The above system of equations can be written as
or AX = B
Where A = B =
and X =
|A| = 10 – 6 = 4
So, the above system has a unique solution, given by
X = A – 1B
Let Cij be the cofactor of aijin A, then
C11 = (– 1)1 + 1 2 = 2
C12 = (– 1)1 + 2 3 = – 3
C21 = (– 1)2 + 1 2 = – 2
C22 = (– 1)2 + 2 2 = 5
Also, adj A =
=
A – 1 =
A – 1 =
Now, X = A – 1B
Hence, X = Y = 4