化简4xy+(-2y²+3xy+x²)-(-5xy+x²+y²)
-3(xy-2x²)-[y²-(5xy-4x²)+2xy]
3x²y+xy²-[2xy²-4x²y+(x²y-2xy²)
化简(3X²-XY+Y²)-5(X²-XY+2Y²)
x-y/x²÷x²-2xy+y²/xy*(xy-x²)
计算 2xy[4x²y²-3y(xy+x²y)-xy²]
化简4xy-3y²-3x²+xy-3xy-2x²+x²-2y²
化简3/(x²+2xy+y²)-4/(x²-2xy+y²)+5/(x²
计算:(xy-x²)×x-y/xy
(2x²y-3xy²)-3(x²y-2xy²)+2(x²y-4xy
x²/xy-x/y
已知(x+1)²+|y-1|=0,求2(xy-5xy²)-(3xy²-xy)得值
计算:x²+2xy+y²/xy-y².x²-2xy+y²/xy+y