下列函数:1.y=-3x+4 2.y=7/5x 3.y=1+2/x 4.y=x²+2 5.y=x-1/2 其中
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
化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1
[(y-2x)(-2x-y)-4(x-2y)²]*2y,其中x=1,y=2
(2x+y-1)(2x-y+1)-(3x+y)(3x-y),其中x=5分之1,
[(2x+y)^2+(y+2x)(y-2x)-2y(4x-y)]/4y,其中x=1/2,y=1/3
先化简,再求值:[(x+y)(x-y)-(x-y)^2+2y(x-3y)]/(-4y),其中x=1,y=-2
化简求值{(x=2y)(5x-2y)-(3x+2y)(3x-2y)]/4x,其中x=2,y=-1
[x(x-y)-y(x-y)+(x+y)(x-y)]÷2x其中x=2012 y=2013
分式的加减:[(x/y-y/x)除以(x+y)+x(1/y-1/x)]除以1+x/y,其中x=5,y=2
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
已知x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(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)+...-(