请大家帮帮忙,我有一道数学题不会做,这是一道因式分解的题,而且要用十字相乘法做!题目是:(x2-7x+6)(x2-x-6)+56请大家写出解题思路,谢谢!(x的二次方减7x加6)乘以(x的二次方减x减6)加56
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/17 16:59:08
![请大家帮帮忙,我有一道数学题不会做,这是一道因式分解的题,而且要用十字相乘法做!题目是:(x2-7x+6)(x2-x-6)+56请大家写出解题思路,谢谢!(x的二次方减7x加6)乘以(x的二次方减x减6)加56](/uploads/image/z/3926678-14-8.jpg?t=%E8%AF%B7%E5%A4%A7%E5%AE%B6%E5%B8%AE%E5%B8%AE%E5%BF%99%2C%E6%88%91%E6%9C%89%E4%B8%80%E9%81%93%E6%95%B0%E5%AD%A6%E9%A2%98%E4%B8%8D%E4%BC%9A%E5%81%9A%2C%E8%BF%99%E6%98%AF%E4%B8%80%E9%81%93%E5%9B%A0%E5%BC%8F%E5%88%86%E8%A7%A3%E7%9A%84%E9%A2%98%2C%E8%80%8C%E4%B8%94%E8%A6%81%E7%94%A8%E5%8D%81%E5%AD%97%E7%9B%B8%E4%B9%98%E6%B3%95%E5%81%9A%21%E9%A2%98%E7%9B%AE%E6%98%AF%EF%BC%9A%EF%BC%88x2-7x%2B6%EF%BC%89%28x2-x-6%29%2B56%E8%AF%B7%E5%A4%A7%E5%AE%B6%E5%86%99%E5%87%BA%E8%A7%A3%E9%A2%98%E6%80%9D%E8%B7%AF%2C%E8%B0%A2%E8%B0%A2%21%EF%BC%88x%E7%9A%84%E4%BA%8C%E6%AC%A1%E6%96%B9%E5%87%8F7x%E5%8A%A06%EF%BC%89%E4%B9%98%E4%BB%A5%EF%BC%88x%E7%9A%84%E4%BA%8C%E6%AC%A1%E6%96%B9%E5%87%8Fx%E5%87%8F6%EF%BC%89%E5%8A%A056)
请大家帮帮忙,我有一道数学题不会做,这是一道因式分解的题,而且要用十字相乘法做!题目是:(x2-7x+6)(x2-x-6)+56请大家写出解题思路,谢谢!(x的二次方减7x加6)乘以(x的二次方减x减6)加56
请大家帮帮忙,我有一道数学题不会做,这是一道因式分解的题,而且要用十字相乘法做!
题目是:(x2-7x+6)(x2-x-6)+56
请大家写出解题思路,谢谢!
(x的二次方减7x加6)乘以(x的二次方减x减6)加56
请大家帮帮忙,我有一道数学题不会做,这是一道因式分解的题,而且要用十字相乘法做!题目是:(x2-7x+6)(x2-x-6)+56请大家写出解题思路,谢谢!(x的二次方减7x加6)乘以(x的二次方减x减6)加56
.(x的平方-7x+6)(x的平方-x-6)+56
=(x-1)(x-6)(x-3)(x+2)+56
=(x-1)(x-3)(x-6)(x+2)+56
=(x2-4x+3)(x2-4x-12)+56
设x2-4x+3=A.得
A*(A-15)+56
=A2-15A+56
=(A-7)(A-8)
=(x2-4x-4)(x2-4x-5)
=(x2-4x-4)(X-5)(X+1)
(x^2-7x+6)(x^2-x-6)+56
=(x-1)(x-6)(x+2)(x-3)+56
=[(x-1)(x-3)][(x+2)(x-6)]+56
=(x^2-4x+3)(x^2-4x-12)+56
=(x^2-4x)^2-9(x^2-4x)+20
=(x^2-4x+4)(x^2-4x+5)
=(x-2)^2*(x^2-4x+5).
(x2-7x+6)(x2-x-6)+56
=(x-6)(x-1)(x-3)(x+2)+56
=[(x-6)(x+2)][(x-3)(x-1)]+56
=(x^2-4x-12)(x^2-4x+3)+56
设x^2-4x-12=A。
原式=A*(A+15)+56
=(A+7)(A+8)
=(x^2-4x-5)(x^2-4x-4)
=(x+1)(x-5)(x-2-2根号2)(x-2+2根号2)