(x-4y)(x-y)-(x+3y)(x-6y)-5x(2-y),其中x=﹣1/3,y=1/2
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
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
(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
已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-(
化简求值(x+2y)^2-(2x+y)(2x-y)-5y(y-x) 其中 x=1/3 y= -1/2
x+y)(x-y)+(x-y)^2-(6x^2y-2xy^2)/2y,其中x=-2,y=1/3
化简求值:(7x-2y)(3x-2y-1)-(4x+3y)(9x+6y),其中x=2,y=-1
先化简,再求值:[(3x-y)(2x+4y)-(x+2y)(5x-2y)],其中x=-2,y=1