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((2x²+y﹚²-5y²(3x²+1)-4(x²+y)(x²

来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/10/06 17:31:40
((2x²+y﹚²-5y²(3x²+1)-4(x²+y)(x²-y))÷5x²y
((2x²+y﹚²-5y²(3x²+1)-4(x²+y)(x²-y))÷5x²y
=(4x^4+4x²y+y²-15x²y²-15y²-4(x^4-y²))÷5x²y
=(4x^4+4x²y+y²-15x²y²-15y²-4x^4+4y²))÷5x²y
=(4x²y-15x²y²-10y²)÷5x²y
=4/5 - 3y -2y/x²
再问: 其中x=99,y=2/15
再答: 刚才有点问题,应该是 ((2x²+y﹚²-5y²(3x²+1)-4(x²+y)(x²-y))÷5x²y =(4x^4+4x²y+y²-15x²y²-5y²-4(x^4-y²))÷5x²y =(4x^4+4x²y+y²-15x²y²-5y²-4x^4+4y²))÷5x²y =(4x²y-15x²y²)÷5x²y =4/5 - 3y =4/5 - 2/5 =2/5
再问: 刚才应该是对的把
再答: 2/5肯定是对的 最上面的那个稍微有点问题 应该是-5y² 而不是-15y²