Question
Use matrix method to solve the following system of equations:
2x + y – z = 1
x – y + z = 2
3x + y – 2z = – 1
Solution
The given equations are
2x + y – z = 1
x – y + z = 2
3x + y – 2 z = – 1
These equations can be written as
Co-factors of the elements of first row of | A | are
i.e. 1, 5, 4 respectively.
Co-factors of the elements of second row of 
are
i.e. 1. – 1, 1 respectively.
Co-factors of the elements of third row of | A | are
i.e. 0, – 3, – 3 respectively.
