⟹ General term:- Tr+1=2nCr(x2)2n−r(1x)r =2nCr⋅x4n−3r 4n−3r=p for xp ∴r=4n−p3 Coefficient =2nCr =2nC4n−p3 =(2n)!(4n−p3)!(2n+p3)!