(xy^-1)²*(-xy^4)^-1*(-y²x^-1)³等于
(xy^-1)²*(-xy^4)^-1*(-y²x^-1)³等于
已知xy大于0求证xy+1/xy+y/x+x/y大于等于4
(-2/3X³y+4x²y²-1/2xy²)/(-xy/4) 急
﹙4x³y²-2x⁴y²-½xy)÷(-1/2xy) (^人^)
【分解因式】 x²-xy+4分之1y² x²y-2xy²+y³ a(x
因式分解xy²-2xy+x+2y-1
因式分解:(x+y)³+2xy-2x²y-2xy²-1
化简求值 已知:(x+2)2;+|y+1|=0求5xy²-{2xy²-[3xy²(4xy&
(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:【4(xy-1)²-(xy+2)(2-xy)】÷¼xy,其中x=-3,y=1/5
化简并求值 xy-2{xy-[3x²y-(xy²+0.5xy)]+4x²y},其中x=1,
(5xy-2x的平方)-3xy-2(3xy-4x的平方)其中x等于1,y等于-2?