The coefficient of x^ky^n-k in the expansion of (x+y)^n equals (k/n)

1) letter c.

2) 4 square root of 9

hope this

step-by-step explanation:

its less than 713.21 but greater than 5.2

(x,y) it'll always be like that.

in this case x is grams and y is ounces.

if there were numbers there, like (5,3)

x would be 5 and y would be 3.