高中基本不等式(x+2y)²=x²+4y²+4xy>=8xy x²+4xy+4y
高中基本不等式(x+2y)²=x²+4y²+4xy>=8xy x²+4xy+4y
4x²+8xy=y²+xy,求x:y=?
已知x²+y²-8x+6y+25=0,求(x-y+4xy/x-y)(x+y-4xy/x+y)
3x²y+xy²-[2xy²-4x²y+(x²y-2xy²)
已知X²+Y²+X²Y²-4XY+1=0 求:(X-Y)^2008-(XY)^2
(2x²y-3xy²)-3(x²y-2xy²)+2(x²y-4xy
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²
-4x²y-8xy²+2x²y-3xy²
化简并求值 xy-2{xy-[3x²y-(xy²+0.5xy)]+4x²y},其中x=1,
已知x²+y²-2x+4y+5=0,求X^4-y^4/2x^2+xy-y²·2x-y/xy
(-x-2y)(x²-2xy+4y²)
已知2X-3√xy-2y=0(x>0)求2x²+xy-9y²分之x²+4xy-16y