先化简,再求值.x²y²-4)(-x²y²-4)-4(xy-1/2)·(xy-1
先化简,再求值.x²y²-4)(-x²y²-4)-4(xy-1/2)·(xy-1
先化简再求值-1/2x²×(2xy²-4x²y²)-4x²y×(-xy
化简并求值 xy-2{xy-[3x²y-(xy²+0.5xy)]+4x²y},其中x=1,
(1)先化简,再求值:[4(xy-1)²-(xy+2)(2-xy)]÷1/4xy,其中x=-2,y=1/5.
先化简,再求值 4(xy²+3xy-2x²y)-[12xy-3(3x²y-2xy²
先化简,再求值 ⒈2(Xy+Xy)-3(Xy-xy)-4Xy,其中X=1,y=-1
先化简,再求值:4(-xy²+3x²y-1)-3(4x²y+2xy²-x),其中
化简求值:[(xy-2)²+4xy-4]÷(xy),其中x=10,y=1/25
先化简 再求值 (x²-4)/(2y+xy) 其中x=-1 y=2
先化简,再求值:3x²—[2x²y—(xy—x²)]+4x²y,其中x=—1,y
先化简,再求值:{xy(x²-3y)+3xy²}(-2xy)+x³y²(2x-y
先化简,再求值:2x²-2y²分之4x²-8xy+4y²乘xy(x-y)分之(x