3(x²-2xy)-2(-3xy+y²)化简
化简(3X²-XY+Y²)-5(X²-XY+2Y²)
3x²y+xy²-[2xy²-4x²y+(x²y-2xy²)
计算 2xy[4x²y²-3y(xy+x²y)-xy²]
化简!1、(x^2-xy)+xy+y^2 2、3(x^2-xy)-xy+y^2
x-y/x²÷x²-2xy+y²/xy*(xy-x²)
-2y³+(3xy²-x²y)-2(xy²-y³)
计算:(-7x²y)(2x²y-3xy³+xy)
求3x²y-2xy²+2(xy-二分之三x²y)-xy+3xy²的值,其中x=3
计算:3xy[2xy-x(y-2)+x]
化简3/(x²+2xy+y²)-4/(x²-2xy+y²)+5/(x²
先去括号,再合并同类项:3x²y-[2xy²-2(xy-2/3x²y)+xy]+3xy
(1)-2分之1xy(3y²-2xy+3x²y)