化简:-x^2y+4x^2y-3yx^2-7x^2y^2+|-8x^2y^2|=( ).
化简:-x^2y+4x^2y-3yx^2-7x^2y^2+|-8x^2y^2|=( ).
y^2-x^2\5x^2-4yx除以x+y\5x-4y
已知x-3y=0,求2x+yx
若|x-y+3|与|x+y-1999|互为相反数,求x+2yx−y
已知x-y=4xy,则2x+3xy-2yx-2xy-y
合并同类项:6x^2y+2xy-3x^2y^2-7x-5yx-4y^2x^2-6x^2y
已知x,y,z 大于0,x+y+z=2,求证 xz/y(y+z)+zy/x(x+y)+yx/z(z+x)大于等于2/3
设2x−yx+y=3,其中x,y≠0,则(2x−3y)3−(3x−2y)3(4x+2y)3−(x−7y)3=( )
已知xy满足x^2+y^2+4/5=2x+y 求代数式yx/x+y的值
设实数x,y满足条件x≥0x≤yx+2y≤3
实数x、y、z满足x=6-3yx+3y-2xy+2z
已知3x-5y=0,则分式x−2yx+3y