We are considering the expansion of the binomial
since n many times, the first term will be the multiplication of a n times with itself so
and the last term will be the multiplication of n times with itself that is
2n, the exponent of b, is even no matter what n is, so
A) is true
B) is not true because if n is odd, the coefficient of a is odd
C) D)
consider the case n=2,
consider the term , the sum of the exponents of a and be is neither n (2) , nor n-1 (1)
Answer: Only A
