如果(x+1)^2+/y+2/=0,求代数式5xy-2/3x^3y^2-4yx+1/2y^2x^3-1/2xy-3x^3y^2-y^2x^3的值5xy-3/2x^3y^2-4yx+1/2y^2x^3-1/2xy-3x^3y^2-y^2x^3

如果(x+1)^2+/y+2/=0,求代数式5xy-2/3x^3y^2-4yx+1/2y^2x^3-1/2xy-3x^3y^2-y^2x^3的值
5xy-3/2x^3y^2-4yx+1/2y^2x^3-1/2xy-3x^3y^2-y^2x^3

没有写错啊
(x+1)^2+/y+2/=0
平方和绝对值的值恒为非负值
只有两数都为0的时候,和才为0
所以x+1=0,y+2=0
x=-1,y=-2
xy=2
5xy-2/3x^3y^2-4yx+1/2y^2x^3-1/2xy-3x^3y^2-y^2x^3
=1/2 x y - 25/6 x^3 y^2
=15+8/3
=17又2/3

(x+1)^2+/y+2/=0
x=-1,y=-2
5xy-2/3x^3y^2-4yx+1/2y^2x^3-1/2x y-3x^3y^2-y^2x^3
=1/2 x y - 25/6 x^3 y^2
=53/3