Question

what will come in the place of .... mentioned above​

Answer 1

Explanation:

consider 1 st case

here the index of 'a' keeps on decreasing till it becomes zero

see the last term b^(n-1)

here you cannot find 'a' so the index of a is 0

consider if n=5 so it is odd

the formula:

a^5+b^5 = (a+b)( a^4 - a^3b + a^2b^2 - ab^3 + b^4)

The index(power) keeps on decreasing....