Question

write the expansion of (x+a)^n

Answer 1

This information can be summarized by the Binomial Theorem: For any positive integer n, the expansion of (x + y)n is C(n, 0)xn + C(n, 1)xn-1y + C(n, 2)xn-2y2 + ... + C(n, n - 1)xyn-1 + C(n, n)yn. Each term r in the expansion of (x + y)n is given by C(n, r - 1)xn-(r-1)yr-1. Example: Write out the expansion of (x + y)7.