A much Box Has Lenght=4cm,width=2+1cm,height=3cm,then Find,surface Area,degree,lead Coffecient,constant Number.

you mean match box?

2+1cm? Why not just say 3cm?
area (3 pairs of faces): 2(4*2 + 4*3 + 3*3)
area is a degree-2 expression (cm^2)

the rest of those items make no sense here. You expecting some kind of polynomial?