Therefore, by using the form of
partial fraction [Table 7 2 (i)], we write
1
(
1) (
2)
x
x
+
+
 =
A
B
1
2
x
x
+
+
+ (1)
where, real numbers A and B are to be determined suitably This gives
1 = A (x + 2) + B (x + 1)