请指教x^2 -3x -10 =0a =1b =-3c =-10x = -(-3) ± √(-3)^2 - 4(1)(-10)x =3 ± √9 -(-40)/ 2x =-3 ±√49 / 2(其实算式不止这么多的,但是到这里我就不懂了,算式开头的那个3 怎么会突然变成 -3 )这就是我的问
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/18 05:32:34
![请指教x^2 -3x -10 =0a =1b =-3c =-10x = -(-3) ± √(-3)^2 - 4(1)(-10)x =3 ± √9 -(-40)/ 2x =-3 ±√49 / 2(其实算式不止这么多的,但是到这里我就不懂了,算式开头的那个3 怎么会突然变成 -3 )这就是我的问](/uploads/image/z/7517992-40-2.jpg?t=%E8%AF%B7%E6%8C%87%E6%95%99x%5E2+-3x+-10+%3D0a+%3D1b+%3D-3c+%3D-10x+%3D+-%28-3%29+%C2%B1+%E2%88%9A%EF%BC%88-3%EF%BC%89%5E2+-+4%281%29%28-10%29x+%3D3+%C2%B1+%E2%88%9A9+-%28-40%29%2F+2x+%3D-3+%C2%B1%E2%88%9A49+%2F+2%EF%BC%88%E5%85%B6%E5%AE%9E%E7%AE%97%E5%BC%8F%E4%B8%8D%E6%AD%A2%E8%BF%99%E4%B9%88%E5%A4%9A%E7%9A%84%2C%E4%BD%86%E6%98%AF%E5%88%B0%E8%BF%99%E9%87%8C%E6%88%91%E5%B0%B1%E4%B8%8D%E6%87%82%E4%BA%86%2C%E7%AE%97%E5%BC%8F%E5%BC%80%E5%A4%B4%E7%9A%84%E9%82%A3%E4%B8%AA3+%E6%80%8E%E4%B9%88%E4%BC%9A%E7%AA%81%E7%84%B6%E5%8F%98%E6%88%90+-3+%EF%BC%89%E8%BF%99%E5%B0%B1%E6%98%AF%E6%88%91%E7%9A%84%E9%97%AE)
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