Question

What is the coefficient of x6y4 in the expansion of (x + y)10?

A. 1
B. 5
C. 210
D. It does not exist.

Answer 1

using combination notation the expansion the general case is

\[^{10}C_{r} x^ry^{10 - r}\]

so in your question you know n = 10 and r = 6

so find the value of the combination

\[^{10}C_{6} =\]