请问(3x²y-2xy²-4xy)·(-4x²y²)=?
3x²y+xy²-[2xy²-4x²y+(x²y-2xy²)
计算 2xy[4x²y²-3y(xy+x²y)-xy²]
x-y/x²÷x²-2xy+y²/xy*(xy-x²)
(2x²y-3xy²)-3(x²y-2xy²)+2(x²y-4xy
去括号:1/2(2X²Y-3XY²+4XY-X²Y²)=?
已知x²+y²-8x+6y+25=0,求(x-y+4xy/x-y)(x+y-4xy/x+y)
2xy-1/2(4xy-8x²y²)+2(3xy-5x²y²),其中x=3/2,
已知x-2y=3,x²-2xy+4y²=11,求下列各值; (1)xy (2)x²-2xy
计算;(xy-x²)÷x²-2xy+y²/xy · x-y/x²
化简3/(x²+2xy+y²)-4/(x²-2xy+y²)+5/(x²
已知2x+y=0,求x-2y/x²+xy*(x²-y²)/x²-4xy+4y
-3(xy-2x²)-[y²-(5xy-4x²)+2xy]