(-1/2x+1/3y)(______)=-1/9y^2+1/4x^2
已知4x=9y求(1)x+y/y (2)y-x/2x
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
若2x+3y-1=y-x-8=x+6,则2x-y=______.
9y=3x-(x-1),4(x+y)-(2x+4)=8y
化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1
1、x(x-y)(x+y)-x(x+y)^2
若|x-y+2|与(x+y-1)2互为相反数,则x=______,y=______.
已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-(
已知(x+y+2)2+|2x-3y-1|=0,则x+y=______.
先化简再求值(x-y)(x+y)-(x-2y) 的完全平方+x(3x-5y)-(x-y)(x-2y),其中x=1/2 y
[(2x+y)^2+(y+2x)(y-2x)-2y(4x-y)]/4y,其中x=1/2,y=1/3
(3x-y)^2+(3x+y)(3x-y),x=1,y=-2