(x-3y)(y+3x)-(x-3y)(3y-x)等于

若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于 已知 2x-3y/y等于2 求x-y/2x 求x-3y/2x+y |x|=3 |y|=5 |x-y|=|x|+|y| 求 X+Y和 X-Y 等于多少 [(3x+y)(x-y)-(2x+3y)(x-y)]*(x-y) 化简:(x-3y)(x+y)-(x-2y)(x+2y)-(x-y)平方 【x-3y][x+y]-[x-2y][x +2y]-[x-y 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-2y)2+(x+2y)(x-2y)-(x-3y)(x-y)计算结果是什么?x等于-4,y等于0.5代入后是多少第一 计算(x+y)(x+y)^2(-x-y)^3 (y-x)(x-y)^3(y-x)^5怎么算 数学(x-y)^5*(y-x)^3*(x-y)^2 已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y