已知x-y=3,求代数式(x+y)(x-y)+(x-y)²-(2xy-2y)²的值

来源:学生作业帮助网 编辑:六六作业网 时间:2024/12/22 11:56:40
已知x-y=3,求代数式(x+y)(x-y)+(x-y)²-(2xy-2y)²的值已知x-y=3,求代数式(x+y)(x-y)+(x-y)²-(2xy-2y)²

已知x-y=3,求代数式(x+y)(x-y)+(x-y)²-(2xy-2y)²的值
已知x-y=3,求代数式(x+y)(x-y)+(x-y)²-(2xy-2y)²的值

已知x-y=3,求代数式(x+y)(x-y)+(x-y)²-(2xy-2y)²的值
﹙x-y﹚﹙x+y+x-y-2y﹚=2﹙x-y﹚﹙x-y﹚=2×3×3=18

(x+y)(x-y)+(x-y)²-(2xy-2y)²
=(x+y)(x-y)+(x-y)²-4y^2(x-1)²
=-4y^2(x-1)²
只能到这了啊

(x+y)(x-y)+(x-y)²-(2xy-2y)²
=(x+y)(x-y)+(x-y)²-4y^2(x-1)²
=-4y^2(x-1)²