Phương trình:
có nhghiệm là:
A.
.
![img1](https://cungthi.online/upload/questionbank3/eduquestion/2019290484233521991/obj2019290484233521991883338_images/obj2019290484233521991883338_img1.png)
B.
.
![img1](https://cungthi.online/upload/questionbank3/eduquestion/2019290484233521991/obj2019290484233521991393838_images/obj2019290484233521991393838_img1.png)
C.
.
![img1](https://cungthi.online/upload/questionbank3/eduquestion/2019290484233521991/obj2019290484233521991821284_images/obj2019290484233521991821284_img1.png)
D.
.
![img1](https://cungthi.online/upload/questionbank3/eduquestion/2019290484233521991/obj2019290484233521991650721_images/obj2019290484233521991650721_img1.png)
Đáp án và lời giải
Đáp án:D
Lời giải:Chọn D
.
Vậy đáp án đúng là D.
![img1](https://cungthi.online/upload/questionbank3/eduquestion/2019290484233521991/obj2019290484233521991858146_images/obj2019290484233521991858146_img1.png)