a) (x + 2y)2 + (x - 2y)(x + 2y
b) (3x - y)2 -- (3x + 5)(3.-55
c) (1 - 5y)2 + (1 + 5y) - 253-2
d) (2 + x)2 + (1 + x)2 - 3+x.

OFER COROANĂ!!!​