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
问题描述:
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
答
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/...