3X+2Y=-1,X-3Y=7,X=?Y=?
已知x-y=1,y≠0,求{(x+2y)²+(2x+y)(x+4y)-3(x+y)(x-y)}÷y的值.
方程组 2x+3y-1=x+6 y-x-8=x+6 怎么解,
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
不解方程组2x+y=6,x-3y=1,求7y(x-3y)的平方-2(3y-x)的立方的值.
(3x-y)^2+(3x+y)(3x-y),x=1,y=-2
若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
已知x和y满足x+3y+|3x-y|=19,2x+y=6,求x,y的值
已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
2(x+y) 3x+3y=24 x+y/2x x y/2y= 1
化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1