The constant term in the expansion of x2+1x2+y+1y8 is

Given expansion x2+1x2+y+1y8=∑8!α!β!γ!δ!x2α1x2βyγ1yδ Here α+β+γ+δ=8α=β,γ=δα=0,β=0 γ=4,δ=4α=1,β=1 γ=3,δ=3α=2,β=2 γ=2,δ=2α=3,β=3 γ=1,δ=1α=4,β=4 γ=0,δ=0 Constant term in the expression =28!0!0!4!4!+28!1!1!3!3!+8!2!2!2!2!=4200