已知X-Y=3,求X-Y的2次幂减3X+3Y+1

已知x-y=3,求[（x+y)(x-y)-(x-y)^2+2y(x-y)]除以的值 已知X-Y=3,求X-Y的2次幂减3X+3Y+1 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 已知x-y=1,求[(x+2y)^2+(2x+y)(x-4y)-3(x+y)(x-y)]除以y的值大神们帮帮忙 已知x-y=1,求[(x+2y)²+(2x+y)(x-4y)-3(x+y)(x-y)]÷y的值 已知(x+2y)(2x-3y)=y(y-4x),试求x/y的值 已知|3x-y|+|x+y|=0,求x-y除以x*y的值. 已知|x|=2,|y|=3,|x+y|=-(x+y)求x-y 已知3x =2y 求x/x+y+y/x-y-y²/x²-y² 已知:3x-5y=0,求x/y,x-y/y,x-y/x 已知（x+y）2 =2,(x-y)3 =3,求(x+y)7(x-y)2(x+y)3(y-x)4 的值 已知2x-y/x+2y=3,求2(2x-y)/x+2y-9(x+2y)/2x-y+3的值. 已知x+y分之x-y=2,求2x+2y分之x-y-3x-3y分之2x+2y的值 已知x+y分之x-y=2,求2x+2y分之x-y-3x-3y分之2x+2y的值 已知2x-y/x+3y=2,求代数式4x-2y/x+3y减4x+12y/2x-y的值 已知2x-y/x+3y=2,求代数式4x-2y/x+3y减4x+12y/2x-y的值 已知x+y分之x-y=2 求x+y分之3x-3y 减x-y分之2(x+y)的值 已知x-y除以x+y=3,求代数式x+y分之2（x-y)-3(x-y)分之x+y的值.