= {[ (2/3)^1010]^2 x (2/3)^20 - (2/3)^2000} x (2/3)^4000 =
{ (2/3)^2020 x (2/3)^20 - (2/3)^2000} x (2/3)^4000 =
{ (2/3)^ 2040 - (2/3)^2000 } x (2/3)^4000 =
(2/3)^2000 { (2/3)^40 - 1} x ( 2/3 ) ^4000 =
(2/3) ^ 6000 {(2/3) ^40 - 1}
P.s . poate am gresit , dar nu este 0