Multiply the binomial and find the coefficients
(X+y)^1=__×+__y

(×+y)^2=__x^2+__xy+__y^2

(X+y)^3=__×^3+__×^2y+__y^3

(×+y)^4=__×^4+__x^3y+__x^2y^2+__xy^3+__y4