2x+y=2 { 4x-y=1怎么算
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
已知4x=9y求(1)x+y/y (2)y-x/2x
2x-y=8 3x+2y=5与3x+2y=1 3x-4y=-11用加减法怎么算?
化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1
整数x,y满足方程2xy+x+y=83,则x+y怎么算
X+Y=5.7 1/4X+2/5Y=4/5X 怎么解
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x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(x-y
[(y-2x)(-2x-y)-4(x-2y)²]*2y,其中x=1,y=2
y=(x+1)(x+2)的反函数怎么算
[(2x+y)^2+(y+2x)(y-2x)-2y(4x-y)]/4y,其中x=1/2,y=1/3
若|x+2y-1|+y²+4y+4=0,求(2x-y)²-2(2x-y)(x+2y)+(x+2y)&