정답
$(a + b)^n = \sum_{k=0}^n \binom{n}{k} a^{n-k} b^k$, where $\binom{n}{k} = \frac{n!}{k!(n - k)!}$.
해설
The general $(k+1)$-th term in the expansion is $T_{k+1} = \binom{n}{k} a^{n-k} b^k$, frequently tested in Gaokao algebra questions.
홈 / 라이브러리 / Gaokao essentials: original practice / AI 플래시카드
What is the Binomial Theorem formula for expanding $(a + b)^n$ for a positive integer $n$?
덱 'Gaokao essentials: original practice'의 플래시카드.