(-2xy^2)^2×3x^2y÷(-x^3y^4)=
利用x-y=3^2009,xy=-3^2010,求代数式:(2x+3y-2xy)-(x+4y+xy)-(3xy+2y-2
[-(x-y)^2/xy]^-4*(y^2-xy/x)^3*(x^4/y^10)÷(xy-y^2/x)^-5=-y(y-
已知;x+y=4,x-y的绝对值=6,求xy(y的平方+y)-y的平方(xy+2x)-3xy
已知x-y=4,xy=-2,求代数式(2x+3y-2xy)-(x+4+xy)-(3xy+2y-2x)的值
已知(x+2)^2+|x+y+5|=0,求3x^2y-[2x^2y-(2xy-x^2y)-4x^2]-xy
已知x+xy=-2,xy-y=-6求代数式2x{-4y-3[(x+xy)²+x]-½[(y-xy
(x+2y-3xy)-(-2x-y+xy),其中x+y=,xy=-,求值.
3x²y+xy²-[2xy²-4x²y+(x²y-2xy²)
1/x-1/y=4,求分式(3x+xy-3y)/(x-2xy-y)
计算:3xy[2xy-x(y-2)+x]
(-3x^y+2xy)-( )=4x^+xy
已知xy=2,x-y=3,求(x+y)(x-y)-y^2-(6x^2y-2xy^2)/2y的值.