(x+y)^{n}=\sum _{k=0}^{n}{n \choose k}x^{n-k}y^{k}=\sum _{k=0}^{n}{n \choose k}x^{k}y^{n-k}.

Some good meth for yo head doode.

Person 1: "Yo, do you know that 2*2 =4 and 2+2= 4."
Person 2: "(x+y)^{n}=\sum _{k=0}^{n}{n \choose k}x^{n-k}y^{k}=\sum _{k=0}^{n}{n \choose k}x^{k}y^{n-k}."

by Lurlei139See December 04, 2018