若x^2y^3
若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于
若变量x,y满足约束条件{x>=-1;y>=x;3x+2y
若3x-5y=0,则x+y/x=(),x-y/y=(),2x-3y/2x+3y=( )
若x=-1/4,能否确定代数式(2x-y)(2x+y)+(2x-y)(y-4x)+2y(y-3x)的值?
若X=负四分之一,能否确定代数式(2X-Y)(2X+Y)+(2X-Y)(Y-4X)+2Y(Y-3X)的值?
若x-y/x+y=5,求x-y/2x+2y+5x+5y/3x-3y的值
若全集I={(x,y)|x,y∈R},集合M={(x,y)|(y-3)/(x-2)},N{(x,y)|y=x=1},则(
[(3x+y)(x-y)-(2x+3y)(x-y)]*(x-y)
化简:(x-3y)(x+y)-(x-2y)(x+2y)-(x-y)平方
【x-3y][x+y]-[x-2y][x +2y]-[x-y
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)+【-
若3x-4y=0,则x/y=______,(x-y)/y=______,(3x+2y)/(2x+3y)=_____.