N, we have:
a) (a - b)n 
(a +(- b))n
Note 1:
It is advisable to remember the following values.
Note 2:
Working rules for expanding
(a + b)n, n 
N
Step 1:
The value of index, n implies that there will be n+1 terms in the expansion of (a + b)n.
Step 2:
Write the first term: nC0anb0.
Step 3:
For the second term, take coefficient as nC1, decreases the power of 'a' by 1 and increases the power of 'b' by 1. Thus,
the second term is nC1an-1b1.
Step 4:
For the third term, take coefficient as nC2, power of 'a' as n-2 and power of 'b' as 2. Continue this process repeatedly till the last term nCna0bn is obtained.
