3.先化简,后求值.2x²y(-2xy²)³+(2xy)³(-xy²)
3.先化简,后求值.2x²y(-2xy²)³+(2xy)³(-xy²)
先化简,再求值:{xy(x²-3y)+3xy²}(-2xy)+x³y²(2x-y
先化简,后求值[(x-y)²-(x+y)]/(2xy) 先化简,后求值[(x-y)²-(x+y)]/
先化简再求值,3xy²(xy+2y²-x²)+3x³y²,其中x=2,
先化简,再求值 4(xy²+3xy-2x²y)-[12xy-3(3x²y-2xy²
先化简再求值(x²+xy-2y²)/(x²-2xy+y²)
数学:先化简再求值(x²+xy-2y²/x²-2xy+y²)-(1-xy
(1)先化简,再求值:[4(xy-1)²-(xy+2)(2-xy)]÷1/4xy,其中x=-2,y=1/5.
化简求值3x²y-[2xy-2(xy-3/2x²y)+xy]+3xy²其中x=3、y=-1
计算:-2x²y(-2xy²)²+(2xy)³·(xy²)
.先化简,后计算.[2x(x²y-xy²)+xy(xy-x²)]/x²yx=20
先化简在求值:(-1/3XY)²×[xy(2x-y)-2x(xy-y)²],其中X=-3/2,Y=2