3x-2y的值

已知x-y=3,求[（x+y)(x-y)-(x-y)^2+2y(x-y)]除以的值 若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 y=3(x-y),x=2(x-y)求x,y的值 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 (x+y)(x+2y)(x+3y)(x+4y)=-40y的值为根号11 先化简再求值{(x-y)(x+y)-(x+y)(x-2y)}/y 其中xy的值是代数式{(3x-2y-7)^2+|2x+3y先化简再求值{(x-y)(x+y)-(x+y)(x-2y)}/y 其中x和y的值是代数式{(3x-2y-7)^2+|2x+3y+4|}^0无意义 x>0x,y>0,求x-y+2-y-x-3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（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+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 当2x-y/x+y=3时,求代数式2x-y/2x+2y+x+y/6x-3y的值. x+2y分之x-y=3,则代数式,x+2y分之2（x-y)-3(x-y)分之x+2y的值为 若x+2y分之x-y=3,则代数式x+2y分之2（x-y)-3(x-y)分之x+2y的值为