x
∵3≤xy2≤8,4≤ x2 y≤9, ∴16≤( x2 y)2≤81, 1 8≤ 1 xy2≤ 1 3 ∴( x2 y)2• 1 xy2∈[2,27] ∵ x3 y4=( x2 y)2•(xy2)−1 ∴ x3 y4∈[2,27]即最大值为27 故选A
设实数x,y满足3≤xy^2≤8,4≤y^2/x≤9,则x^3/y^4的最大值是
设x,y为实数,满足3≤xy^2≤8,4≤x^2/y≤9,则x^3/y^4的最大值是
设实数x,y,满足3≤xy²≤8,4≤x²/y≤9,则x³÷y∧4的最大值是多少
设实数x,y满足x-y-2≤0x+2y-4≥02y-3≤0,则yx的最大值是 ___ .
已知实数x、y满足x+y+xy=9,x2y+xy2=20,求x2+y2的值.
若实数x,y满足xy+x+y+7=0,3x+3y=9+2xy,则x2y+xy2=______.
数学竞赛题:若实数x,y满足方程组xy+x+y+7=0,3x+3y=9+2xy,则x2y+xy2=?
已知实数x,y满足条件x≥0,y≥x,3x+4y≤12,则(x+2y+3)/(x +1)的最大值是
设实数x,y满足3x2+2y2≤6,则P=2x+y的最大值为( )
4x2y-{x2y-「3xy2 – 1/ 2(4x2y-8xy2)+x2y」}-5xy2
一直实数X,Y满足{Y≤2X,Y≤4,X-2Y+3≤0}则X+Y-8的最大值为__
若x-y=3,xy=-2,则xy2-x2y的值是______.
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