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