Răspuns :
2021+2x(2020x2021)/2=2021+2020x2021=2021(1+2020)=2021*2021=2021²
A =2021 + 2 x 2020 x 2021 :2
A =2021 ( 2020 + 1 )
A= 202`1 x 2021
A= 2021 la puterea a 2 ( deci e patrt perfect
A =2021 ( 2020 + 1 )
A= 202`1 x 2021
A= 2021 la puterea a 2 ( deci e patrt perfect