(2X+Y)(X-2Y)-2X(X+Y)化简

来源：学生作业帮编辑：大师作文网作业帮分类：数学作业时间：2024/11/13 17:10:42

解(2X+Y)(X-2Y)-2X(X+Y)
=（2X²-4xy+xy-2y²）-（2x²-2xy）
=-2y²-5xy
再问：其中xy满足X²+y²—2x+4y=—5
再答：解 x^2+y^2-2x-4y+5=0 (x^2-2x+1)+(y^2-4y+4)=0 (x-1)^2+(y-2)^2=0 ∴(x-1)^2＝0 (y-2)^2＝0 ∴x-1=0 x=1 ∴y-2=0 y=2 所以 x=1, y=2 带入得-2²-5*1*2=-14

1、x(x-y)(x+y)-x(x+y)^2 化简:(x-3y)(x+y)-(x-2y)(x+2y)-(x-y)平方化简：（2x-y)²-4(x-y)(x+y) (1)(x^2/x)-y-x-y 【(x-y)^2+(x+y)(x-y)】除以 2x 化简(y-x)(z-x)/(x-2y+z)(x+y-2z)+（z-y)(x-y)/(x-2z+y)(y+z-2x)+(x 有这样一道题:"计算(2*x*x*x-3*x*x*y-2*x*y*y)-(x*x*x-2*x*y*y+y*y*y)+【- x^2-y^2/x+y-4x(x-y)+y^2/2x-y, (x+y)^2(x-y)^2-(x-y)(x+y)(x^2+y^2)分解因式化简：{2/3x-2/(x+y)[(x+y)/3x-x-y]}/【(x-y)/x】的负二次方【x-3y][x+y]-[x-2y][x +2y]-[x-y [(3x+y)(x-y)-(2x+3y)(x-y)]*(x-y)