（-3x^2)^3X(-4y^3)^2/(6x^2y)^3

x+y/2+x-y/3=6,4(x+y)-3(x-y)=-20 {(x+y)/2+(x-y)/3=6 4(x+y)-3(x-y)=-20 4(x+y)-3(x-y)=-20,2/x+y+3/x-y=6 {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 因式分解3x^2(x-y)+6x(y-x) x/x-y*y^2/x+y-x^3y2/x^4-y^4/x^2/x^2+y^2 x^8-x^7y+x^6y^2-x^5y^3+x^4y^4-x^3y^5+x^2y^-xy^7+y^8 1.（（y+2x)(-2x+y)+4(x+2y)^2)/3y 2.（2(x-y)^3-8(x-y）^2(x+y)+6y( (x+3y-4)(2x-y) [(x+y)^3]^6-3[(x+y)^3]^6X(x+y)^4X(-x-y)^2 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)+【- [(3x+y)(x-y)-(2x+3y)(x-y)]*(x-y)