3X²+5XY+3Y²

-3(xy-2x²)-[y²-(5xy-4x²)+2xy] 化简（3X²-XY+Y²）-5(X²-XY+2Y²） 若x²+xy+5y=3,y²+xy+5x=-3,求x+y的值. 若x²+xy+5y=3,y²+xy+5x=-3,求x+y的值 若x²+xy+5y=3,y²+xy+5x=-3,求x+y旳值 1/x+1/y=5,求2x-3xy+2y/x²+xy+y的值 已知(x+1)²+|y-1|=0,求2(xy-5xy²)-(3xy²-xy)得值 已知x+y=3 xy=-5 求x设abc=1 求x²+3xy+2y²/x²y+2xy
3x²y+xy²-[2xy²-4x²y+（x²y-2xy²） (2x²y-3xy²)-3(x²y-2xy²)+2（x²y-4xy&# (3xy)² · (x²+xy-y²)-3xy(3x³y+3x²y&# 先化简,再求值:{xy(x²-3y)+3xy²}(-2xy)+x³y²(2x-y