y=2x-…

数学题……555{(3x+y)(3x-y)-(x-5y)(5x-y)-(x-2y)²÷(-4x),x=-2.y [x(x-y)-y(x-y)+(x+y)(x-y)]÷2x其中x=2012 y=2013 当x=1/2,y=1/3时,求代数式x-(x+y)+(x+2y)-(x+3y)+…-(x+101y)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) y'-2y=(e^x)-x y'+2y/x=x通解 已知x=2,y=3,求代数式（x-y）*（x-y）^3*(x-y)^5*……*(x-y)^11 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= 数学题已知p=x^/x-y-y^/x-y,q=(x+y)^-2Y(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 (3x-y)^2+(3x+y)(3x-y),x=1,y=-2