Answer: T₅.
- A T₄
- B T₆
- C T₇
- D T₅
Correct answer: D. T₅
Explanation: n=8 (even). Middle term = T(8/2+1) = T<sub>5</sub>.
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