Question

利用分解因式：1-2345²+0.7655²+2.469×0.7655

Answer 1

0.2345²+0.7655²+2.469×0.7655
=0.2345^2+2*0.2345*0.7655+0.7655^2
=(0.2345+0.7655)^2
=1^2
=1

追问

是一减后面的。。漏掉了

追答

1-[0.2345²+0.7655²+2.469×0.7655]
=1-[0.2345^2+2*0.2345*0.7655+0.7655^2]
=1-(0.2345+0.7655)^2
=1-1^2
=(1+1)(1-1)
=2*0
=0

追问

减号后面加括号里面符号要变号吧。。

追答

我晕了
你的题目是：1-2345²+0.7655²+2.469×0.7655还是 1-0.2345²+0.7655²+2.469*0.7655还是1-（2345²+0.7655²+2.469×0.7655）还是啊1.2345²+0.7655²+2.469×0.7655
~~~到底是哪一个？？
1-0.2345²+0.7655²+2.469*0.7655
=（1+0.2345）（1-0.2345）+0.7655+2.469*0.7655^2
=（1.2345+0.7655+2.469）*0.7655
=。。。。
1.2345²+0.7655²+2.469×0.7655这个看我下楼的

追问

呵呵。。。。是1-23452+0.76552+2.469×0.7655

追答

2345^2....这个还是用计算器算吧~~~我晕了 为啥不是1-0.2345^2

Answer 2

1.2345²+0.7655²+2.469×0.7655
=1.2345²+2×1.2345×0.7655+0.7655²
=（1.2345+0.7655）²
=4

Answer 3

乱码