Answer: bⁿ.
- A aⁿ
- B nab
- C nCn aⁿ
- D bⁿ
Correct answer: D. bⁿ
Explanation: The last term T(n+1) = nCn a<sup>0</sup> b<sup>n</sup> = b<sup>n.</sup>
Row n of Pascal's triangle gives the coefficients nC0, nC1, ..., nCn for the expansion of (a+b)ⁿ; each number is the sum of the two numbers diagonally above it, a direct visual proof of the identity nCr = (n-1)C(r-1) + (n-1)Cr.
Concept context
Expansion of (a+b) n , general term, middle term, binomial coefficients, and greatest term