问题
选择题
方程x2+|x|-1=0所有实数根的和等于（ ）
|
答案
①当x≥0时；原方程可化为，x2+x-1=0，方程的根为：x=
；
-15 2
②当x＜0时；原方程可化为，x2-x-1=0，方程的根为：x=
；-
+15 2
∴所有实数根的和
+
-15 2
=0-
+15 2
故选C．
搜题请搜索小程序“爱下问搜题”
方程x2+|x|-1=0所有实数根的和等于（ ）
|
①当x≥0时；原方程可化为，x2+x-1=0，方程的根为：x=
；
-15 2
②当x＜0时；原方程可化为，x2-x-1=0，方程的根为：x=
；-
+15 2
∴所有实数根的和
+
-15 2
=0-
+15 2
故选C．
| 从对话后的选项中选择适当的选项补全对话。 | |
| Susan and Harry arrive in a Tai restaurant. Somsak: The owner, comes out to greet them. Somsak: Ah! Miss Stewart! 1_______ How are you? Susan: Fine, Somsak. And you? Somsak: Fine, thank you. Susan: 2_______ Harry: Pleased to meet you, Somsak: 3_______ Any friend of Miss Stewart's is welcome. Somsak: Follow me, please. Harry: [to Susan] I like it here. Susan: 4_______ I come here often. Somsak: A special place for special people. Susan: Thank you. Somsak.
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