原式=(1-x)²-4(1-x²)+4(1+x)² =(8/3)²-4(-16/9)+4(-2/3)² =64/9+64/9+16/9 =144/9 =16
原式=(1-x)²-4(1+x)(1-x)+4(1+x)²=[(1-x)-2(1+x)]²=(-1-3x)²=(-1+5)²=16
