化简求值[x(x²y²-xy)-y(x²-x²y²)]÷3x²
化简求值[1-(2x/x+y)]÷ (x²-2xy+y²/3x+3y)+(x²+xy/x&
化简求值:x-y/x²-2xy+y²-xy+y²/x²-y²,其中(x
化简求值:(X×根号X+X×根号y)÷(XY-Y²)-(X+根号XY+Y)÷X×根号X-Y×根号Y,其中X=1
1.化简求值:(x+y)(x-y)-(x-y)²-6x²y÷2y+(2xy)²÷(-4xy
化简求值:(x+y)(x-y)+(x-y)²-(6x²y-2xy²)÷2y,其中x=-2,
先化简在求值(x+y)²-(x-y)(x+y)-(xy)²÷(xy),其中x,y是方程组『3x+2y
先化简,再求值,先化简,再求值,【1/(x-y)】-【1/(x+y)】/【xy²/(x²-y
化简求值:(2x²y-2xy²)-【(-3x²y²+3x²y)】,其中
化简求值:3(2X²Y-3XY²)-2(2XY²-3X²Y),其中X=1,Y=-
x-y/x²÷x²-2xy+y²/xy*(xy-x²)
先化简再求值:2x²+(-x²+3xy+2y²)-(-x²-xy+2y²
化简求值3x[xy-2x(y-2x)]+3y(x²-y²),其中x=-1,y=2