2x²-5xy+2y²+3x-3y+1
计算3x[xy-2x(1/y-x/3]+3y(x²-y²)
1/x+1/y=5,求2x-3xy+2y/x²+xy+y的值
已知x+y=3 xy=-5 求x设abc=1 求x²+3xy+2y²/x²y+2xy
化简 (x+y)(x²-xy+y²) ; 3(2x-1)(x+6)-5(x-3)(x+6)
求3xy²-4x²y-2xy²+ 5x²y的值,其中x,y满足|x-1|+(y+
若x=1/2,y=1 求x(x²+xy+y²)-y(x²+xy+y²)+3xy(
化简(3X²-XY+Y²)-5(X²-XY+2Y²)
下列多项式:(1)x²+xy-y²;(2)-x²+2xy-y²;(3)xy+x&
急![(3x+y)²-3(3x-y)(x+y)-(x-3y)(x+3y)]÷(2xy)
4x²y-1/2{x²y-[5x²y-2(2xy²+1/4xy)]}+3xy
1、(-7x^y)(2x^y-3xy^3+xy) 2、((x-y)^6)/((y-x)^3)/(x-y)
(2x²y-3xy²)-3(x²y-2xy²)+2(x²y-4xy