Which statement about the simplified binomial expansion of (a + b2)n, where n is a positive integer, is true?
a. the exponent of b will always be even.
b. the exponent of a will always be odd.
c. the sum of the exponents of a and b will always equal n.
d. the sum of the exponents of a and b will always equal n – 1.

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)

Only A