9 Efectuați:
a (2x + 1)³+ (x + 2)³ + (x - 2)(x + 2);
c (x - 3y)³ + (y + 2)³+ (x + y - 2)2²
e (4 - 3x)² – (3x – 4)²+ (3x - 4)³
b (x - 1)³ + (2 - x)³ - (x + 3)²
d (x - 2y + 2)² + (x + 1)³- (y + 2)²
f (x + 2y)³+ (x + 2y)² – (x + 2y + 1)²​