【(3x+2y)(3x-2y)-(x+2y)(5x-2y)】÷8x=? 要答案,要过程

(3x+y)二次方-3(3x-y)(x+y)-(x-2y)(x+3y)要过程! 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 计算(2x+y)(3x-2y) 要过程 （3x+y)(x-2y)计算要过程 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= 先化简再求值(x-y)(x+y)-(x-2y) 的完全平方+x(3x-5y)-(x-y)(x-2y),其中x=1/2 y 化简求值,要详细过程[(y-2x)(-2x-y)-4(x-2y)^2]÷3y,其中x=1,y=-2 数学(x-y)^5*(y-x)^3*(x-y)^2 化简求值,要详细过程[(y-2x)(-2x-y)-4(x-2y)²]÷3y,其中x=1,y=-3 数学题……555{(3x+y)(3x-y)-(x-5y)(5x-y)-(x-2y)²÷(-4x),x=-2.y 已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y [(x+2y)^2 -(x+y)(3x-y)-5y^2]÷2x