Example 2 Evaluate 
1
x– 1
x
x
x
+
Solution We have
1
x– 1
x
x
x
+
 = x (x) – (x + 1) (x – 1)  = x2 – (x2 – 1) = x2 – x2 + 1 = 1
4 2 3  Determinant of a matrix of order 3 × 3
Determinant of a matrix of order three can be determined by expressing it in terms of
second order determinants This is known as expansion of a determinant along
a row (or a column)