x2-2xy+y2-9

x2-2xy+y2-9 计算(x+y/x-y + 4xy/y2-x2)(x2-9y2)/（x2+2xy-3y2） (3xy-9x2-2y2-6xy)-(6x2+2xy-3xy-y) (x2+2xy+y2)( x2-xy+y2)2 化简 (x2-2xy+y2)-(x2+2xy+y2)=什么 ( x2+xy+y2) ( x2+xy+2y2)-12y4 25(x2+ 2xy +y2)-9(x2-2xy+y2)因式分解.x2,y2是x平方,y平方的意思.2xy就是2xy.快, 计算：(xy-x2)÷xy分之x2-2xy+y2 求证:(x2-xy+y2)3+(x2+xy+y2)3能被2x2+2y2整除 若X2+xy-2y2=0,则（x2+3xy+y2)/x2+y2=? (x2+y2)(x2-xy+y2)-2x2y2因式分解 (x2+xy+y2)-4xy(x2+y2) 解方程组 ｛3x2-y2=8 {4x2+12xy+9y2=1 {x2+2xy+y2-4=0 x2+xy+y2=4 4x2-9y2=0 x2-2xy+y2-1=0还有{x2+y2=4xy-y2+4=0x2-----x的平方 y2------y的平方 还有{2x-3y=12x2-3xy+y2-4x+3y-3=0 2xy+9-x2（平方）-y2（平方） x2一2xy十y2一9 2xy-x2-y2+9分解因死式 因式分解:25(x2+2xy+y2)-9(x2-2xy+y2)大神在哪里.速度解决++++分. 4x2-3y2+2xy-4x2+5x2