(x+y+z)(x+y+z)(x+2)(x+y-2)

(3) (x+y+2)(-x+y+2)(x−y+2)(x+y−2) ={x+(y+2)}{−x+(y+z)}×{x-(y-2)}{x+(y-z)} ={(y+2)²-x2}{x²-(y-2)²) Du ={-x2+(y+z)^}{x(y-2)^} =-x+{(y+2)²+(y-2)²x²-(y+z)² (y-z)² =-x+2(y2+22)x2(y2-22)2 =-x-y'-'+2x²y²+2y'z²+2x²x²