9(x-y)²-12(y²-x²)+4(x+y)²

来源：学生作业帮助网编辑：六六作业网时间：2024/12/19 10:23:53

9(x-y)²-12(y²-x²)+4(x+y)²9(x-y)²-12(y²-x²)+4(x+y)²9(x-y)

9(x-y)²-12(y²-x²)+4(x+y)²
9(x-y)²-12(y²-x²)+4(x+y)²

9(x-y)²-12(y²-x²)+4(x+y)²
9(x-y)²-12(y²-x²)+4(x+y)²
＝[3(x-y)]²+2·[3(x-y)]·[2(x+y)]+[2(x+y)]²
＝[3(x-y)+2(x+y)]²
＝(5x-y)².