(3xy)² · (x²+xy-y²)-3xy(3x³y+3x²y
(3xy)² · (x²+xy-y²)-3xy(3x³y+3x²y
先化简,再求值:{xy(x²-3y)+3xy²}(-2xy)+x³y²(2x-y
3x²y+xy²-[2xy²-4x²y+(x²y-2xy²)
(2x²y-3xy²)-3(x²y-2xy²)+2(x²y-4xy
-2y³+(3xy²-x²y)-2(xy²-y³)
x²-2xy+y²分之x²+2xy-3y³如何因式分解
计算:(-7x²y)(2x²y-3xy³+xy)
计算:(xy-x²)×x-y/xy
(x-y)²-(3x-3xy+y²)因式分解
-3(xy-2x²)-[y²-(5xy-4x²)+2xy]
已知x:y=3:2,求(x²+3xy)/(xy+2xy)
计算 2xy[4x²y²-3y(xy+x²y)-xy²]