①x^4-4x^3y+4x^2y^2②(2x+3y)^2-(2x-y)^2高手帮帮忙

x/x-y*y^2/x+y-x^3y2/x^4-y^4/x^2/x^2+y^2 (x+3y-4)(2x-y) (2x+y)(2x-3y)+x(2y+y) 2a(x-y)-4b(x-y) x^2-y^2/x+y-4x(x-y)+y^2/2x-y, 计算【3(x-y)^2(x+y)^-2/4(x+y)^2(x-y)^-2】^-2 (2x-y)(2x+y)-2(3x-4y)(4y+3x) （x+2)(x+3) (x-4)(x+1) (y+4)(y-2) (y-5)(y-3) 计算（2x-3y)(x+4y)-(3x+y)(x-2y) (x-3y)(y+2x)-(4y-3x)(3x+4y)计算 {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 把(x+3y)(3x-4y)-(x-2y)(x+3y)分解因式! x+y/2+x-y/3=6,4(x+y)-3(x-y)=-20