Tìm x, y: (x + y)^2020 + |2021 - y| ≤ 0

Tìm x,y:
a, ( x + y )^2020 + I 2021 - y I ≤ 0
b, I 3x + 2y I^209 + I 4y - 1 I^2020 ≤ 0