-(x2²-2xy-y²)+(5x²-2xy-3y²)化简
化简(3X²-XY+Y²)-5(X²-XY+2Y²)
已知x2+y2=9,xy=-3,求多项式5x²-3xy-5y²-11xy-8x²+2y
-3(xy-2x²)-[y²-(5xy-4x²)+2xy]
化简4xy-3y²-3x²+xy-3xy-2x²+x²-2y²
计算:x²+2xy+y²/xy-y².x²-2xy+y²/xy+y
化简-3x²y+2x²y+3xy²-2xy²
x-y/x²÷x²-2xy+y²/xy*(xy-x²)
已知(x+1)²+|y-1|=0,求2(xy-5xy²)-(3xy²-xy)得值
3x²y+xy²-[2xy²-4x²y+(x²y-2xy²)
(2x²y-3xy²)-3(x²y-2xy²)+2(x²y-4xy
先化简,再求值:{xy(x²-3y)+3xy²}(-2xy)+x³y²(2x-y
化简2XY+(X-Y)²