Đáp án+Giải thích các bước giải:
1,
$\dfrac{\sqrt{3x-1}}{\sqrt{x+2}}=\sqrt{5}$$Đk:$$\begin{cases} 3x-1≥0\\x+2>0 \end{cases}$
$⇔\begin{cases} 3x≥1\\x≥-2\end{cases}$$⇔\begin{cases}x≥\dfrac{1}{3}\\x≥-2\end{cases}$$⇒x≥\dfrac{1}{3}$
3x-1 > hoặc = 0
x > hoặc = 1/3
x+2 > 0
x > - 2
rút gọn biểu thức `A=(2^12 .3^5-4^6 .81)/((2^2. 3)^6+8^4. 3^5)` `B=(30. 4^7. 3^29-5.14^5. 2^12)/(54. 6^14. 9^7-12.8^5. 7^5)`
Bài 1:Viết lại câu sao cho nghĩa của câu ko đổi. 1, I love to watch cartoons on TV. I love................................................ 2, I prefer reading in bed I prefer............................................. 3, Does Trung hate to do morning exercises? Does................................................ 4, We love to skateboard in the park after school. We love........................................... 5, My brother doesnot like watching documentaries. My brother...................................... 6, Does she prefer to what TV during her meals? Does she........................................ 7, They love sunbathing and swimming. They love......................................
Rewrite sentences 1. People say that the thief has escaped from the prison -> It is said that -> He is 2. My sister got me to buy her some flowers -> My sister got flowers 3. Your dress needs shortening -> Your dress needs to 4. It’s essential to improve your english -> Your english 5. They watched him climb the tree -> He was 6. He didn’t invite me to the class meeting -> I 7. I saw him walking along the streets -> He 8. My dad allowed my elder brother to stay up late on Saturdays -> My elder brother 9. John gets his sister to clean his shirt -> John gets his shirt 10. She reported that the flowers were killed by frost -> It was -> The flowers giúp mình với ạ
Mình đang cần gấp mình sẽ cho 5 sao
Dùng 1,568 lit khí hiđro (đktc) để khử 3,2 gam sắt (III) oxit (Fe2O3) . Giả thiết phản ứng xảy ra hoàn toàn theo phương trình hóa học: Fe2O3 + 3H2 --> Fe + 3H2O. Hãy cho biết: a) Hãy cho biết khí hiđro hay Fe2O3 còn dư? Tính lượng dư. b) Khối lượng sinh ra là bao nhiêu?
làm cho mình con 2A + 3B -5C thôi nhé
Phân tích đa thức thành nhân tử: x^2 + 4x + 4 x^3 - 3x^ + 3x - 1
Exercise 6: Điền từ nối thích hợp vào chỗ trống 1) I requested him many times, _________ he did not relent. 2) He is working hard, ___________ he is making a progress. 3) ________John is not going to the party, his wife wants to go. 4) Julie wants to eat out; _________, she is low on budget. 5) You are in to the game, ________ you are out of it. 6) He was scared, _________ he acted bravely. 7) Barbie was angry, _________ nobody spoke to her. 8) _________he had many options, he chose to stay with you. 9) She is writing a letter, _________ she is going to regret it later. 10) He was sad________ he lost his purse. 11) They were talking _______ no teacher was present. 12) He tried really hard; ________ , he failed to achieve. 2 Tài liệu tiếng Anh ôn tập hè 7 - 8 GV: Kiều Thị Thu Hà - THCS BM 13) You are driving fast, _________ we will be late for the meeting. 14) He is going through a tough time, __________ he is calm and composed. 15) You did him a favor, _________ he is returning it by helping you. 16) She is calling you continuously ________ you are not receiving her call. 17) Teachers should always talk to a sad child _________ he might need help. 18) He is not going to the party, _________ he will not let you go. 19) ___________ Julie was sad, she presented a happy face. 20) They were composed; _________ ,they were calm.
Verb form 1. I promise I (try) (win) a place at university. 2. He (be) in good health lately 3. I (save) 500, 000 so far. 4. Tom never (be) here before 5. We (not finish) (build) the house yet. 6. I wish I (be) a fashion designer. 7. Peter (not phone) me since he (leave) for Phong Nha Cave. 8. Would you like (come) for dinner? 9. I can’t help (laugh) when he tells jokes. II. Word form 1. (attract). Our craft village is one of the most famous __________where tourists can make handicrafts by themselves. 2. (enjoy) She said the trip to that place was ________. 3. (impress). I was very __________by the way theu made things. 4. (history). There are many __________places in this city.
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