原式=(y+2-1)4+(y+2+1)4-272令x=y+2原式=(x-1)4+(x+1)4-2722(x4+6x2+1)-272=2(x4+6x2-135)=2(x2-9)(x2+15)=2(x+3)(x-3)(x2+15)=2(y+5)(y-1)(y2+4y+19)
