化简:1/xy+1/(x+4)(y+4)+1/(x+8)(y+8)+1/(x+12)(y+12)+……+1/(x+4n)
若x+y=-1,则x^4+5x^3y+x^2y+8x^2y^2+xy^2+5xy^3+y^4=( )
4/X+1/Y=2,XY=-1,求代数式4Y-X/X-2Y/(x+2y-12Y²/x-2y)的值
麻烦你们团队了:计算:1、(6xy^2-12x^3y^4+2x^2y^2)/(-2xy^2) 2、8(x-y)^4(x+
(1)1-a/a*a-2a+1 (2)3x-4y/8xy-6x*x (3)2x*xy(x-y)/12xy*y(y-x)
x²+xy/(x-4y)(x+y),其中x=4,y=-1
xy-1+x-y
先化简,再求值(4x^2-2xy+y^2)(2x+y)-(x^2-y^2)(8x-y),其中x=1,y=-2
分解因式(x^2+3x+2)(3+8x+4x^2)-90xy(xy+1)+(xy+3)-2(x+y+0.5)-(x+y-
4(x-y)^n+1-3(y-x)^n
多项式因式分解 1,(x-y)³-(x-y)²(x+y) 2,x(x²-xy)-(4x
先化简再求值(x+y)(x-y)-(4x的立方y-8xy的立方)/2xy,其中x=-1,y=3/根号3
先化简,再求值(x-y/x+y)^2÷(y-x/x^2+2xy+y^2)^2*1/x+y,其中x=-4,y=1