99 ! i have 10 minutes ! which statement about the simplified binomial expansion of (a – b)n, where n is a positive integer, is true? a. all terms of the expansion are positive. b. all terms in the expansion are negative. c. the first term in the expansion is positive. d. the first term in the expansion is negative.

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

10

step-by-step explanation: