①解不等式(x+9)²>2(x-9)(x-1)(x-1)² ②x+1/x=3,求x²+1/x²的值帮忙解一下!O(∩_∩)O谢谢!
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/04 23:38:16
![①解不等式(x+9)²>2(x-9)(x-1)(x-1)² ②x+1/x=3,求x²+1/x²的值帮忙解一下!O(∩_∩)O谢谢!](/uploads/image/z/6799811-59-1.jpg?t=%E2%91%A0%E8%A7%A3%E4%B8%8D%E7%AD%89%E5%BC%8F%EF%BC%88x%2B9%EF%BC%89%26%23178%3B%EF%BC%9E2%EF%BC%88x-9%EF%BC%89%EF%BC%88x-1%EF%BC%89%28x-1%29%26%23178%3B+%E2%91%A1x%2B1%2Fx%3D3%2C%E6%B1%82x%26%23178%3B%2B1%2Fx%26%23178%3B%E7%9A%84%E5%80%BC%E5%B8%AE%E5%BF%99%E8%A7%A3%E4%B8%80%E4%B8%8B%21O%28%E2%88%A9_%E2%88%A9%29O%E8%B0%A2%E8%B0%A2%21)
①解不等式(x+9)²>2(x-9)(x-1)(x-1)² ②x+1/x=3,求x²+1/x²的值帮忙解一下!O(∩_∩)O谢谢!
①解不等式(x+9)²>2(x-9)(x-1)(x-1)² ②x+1/x=3,求x²+1/x²的值
帮忙解一下!
O(∩_∩)O谢谢!
①解不等式(x+9)²>2(x-9)(x-1)(x-1)² ②x+1/x=3,求x²+1/x²的值帮忙解一下!O(∩_∩)O谢谢!
(x+9)²>2(x-9)(x-1)-(x-1)²
x²+18x+81>2(x²-10x+9)-(x²-2x+1)
x²+18x+81>2x²-20x+18-x²+2x-1
x²-2x²+x²+20x-2x+18x+81-18+1>0
36x+64>0
x>-64/36=-16/9
②
x²+1/x²
=(x+1/x)²-2
=3²-2
=9-2
=7