Đáp án:
`C(x)=x^2-2x+5`
Ta có: `x^2-2x+5`
`=x^2-2x+1+4`
`=x^2-x-x+1+4`
`=x.(x-1)-1.(x-1)+4`
`=(x-1).(x-1)+4`
`=(x-1)^2+4`
Vì `(x-1)^2≥0∀x`
`->(x-1)^2+4≥4>0∀x`
`->` Không có giá trị nào của `x` để `C(x)=0`
Vậy đa thức `C(x)` vô nghiệm.
Đáp án+Giải thích các bước giải:
Đặt `C(x)=0`
Ta có: `x^2-2x+5=0`
`<=> x^2-2x+1+4=0`
`<=> (x-1)^2=-4`(vô nghiệm)
Vậy đa thức `C(x)` vô nghiệm
Task 2: Choose the best answer among A, B, C, or D. 1. “You _______________ hard today.” - Yes, I have a lot to do a. is working b. are working c.am working d. work 2. My father _______________ excuses when I feel like going to the cinema. a. make always b. always make c. always makes d. always making 3. I _______________ Christine. Do you know where she is? a. is looking b. are looking c. am looking d. look 4. It _______________ dark. Shall I turn on the light? a. is geting b. getting c. is getting d. are getting 5. They don’t have any where to live at the moment. They _______________ with friends until they find somewhere. a. is staying b. are staying c. am staying d. stay
Choose the words from the list to fill in If-clauses and complete the main clauses with the words in parentheses. One word is not used.
1. I don't like the way Sue thinks she's more important than everyone else. (STOP) I wish _________ on everyone else. 2. I hardly ever wear sunglasses as I find the annoying. (USED) I am __________________________________ sunglasses because I don´t like them. VUI LÒNG GIẢI THÍCH CHO MÌNH NỮA Ạ
giúp mình với ạ hứa sẽ vote và cảm ơn ạ IX – Combine each of the following pairs of sentences into one sentences, using (not) adj + enough + to infinitive. 1. My sister is old. She can drive a car. ............................................................................................................... .2. The radio isn’t small. You can’t put it in your pocket................................................................................................................. 3. This coat isn’t warm. I don’t wear it in winter................................................................................................................. 4. She is beautiful and intelligent. She can become Miss World................................................................................................................ .5. The weather was fine. We could go camping................................................................................................................. 6. Thoes apples aren’t ripe. We can’t eat them................................................................................................................. 7. Mr. Robinson ins’t rich. He can’t buy a house................................................................................................................. 8. The worker is clever. He can make fine things from wood..........................................................................................
chỉ cần đáp án ko cần giải chi tiết
Giải hộ mk nha Cảm ơn bạn nhiều 😇😇😇😇
bài 4 nha mn.làm câu nào cx đc nhưng làm hết thì vote 5*
chụp hơi mờ,mog mọi ng giải hộ ạ cảm ơn nhiều
Task 1: Supply the correct form of the verb. 5. What he (do) ______________ at present? - He (read) _______________ a very funny comic. 6. The children (play) _______________ in the park at the moment. 7. It is ten o’clock in the morning. We (stay) _______________ at home. I (play) _______________ video games and my sister (read) _______________ a book in her room.
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