a) Đúng. Vì √0,0001=√0,012=0,010,0001=0,012=0,01

Vì  VP=√0,0001=√0,012=0,01=VTVP=0,0001=0,012=0,01=VT. 

b) Sai. 

Vì vế phải không có nghĩa do số âm không có căn bậc hai.

c) Đúng.

Vì: 36<39<4936<39<49  ⇔√36<√39<√49⇔36<39<49

                                 ⇔√62<√39<√72⇔62<39<72

                                 ⇔6<√39<7⇔6<39<7

Hay √39>639>6 và √39<739<7.

d) Đúng. 

Xét bất phương trình đề cho:

                  (4−√13).2x<√3.(4−√13)(4−13).2x<3.(4−13)     (1)(1)

Ta có: 

16>13⇔√16>√1316>13⇔16>13

                       ⇔√42>√13⇔42>13

                       ⇔4>√13⇔4>13

                       ⇔4−√13>0⇔4−13>0

Chia cả hai vế của bất đẳng thức (1)(1) cho số dương (4−√13)(4−13), ta được:

                         (4−√13).2x(4−√13)<√3.(4−√13)(4−√13)(4−13).2x(4−13)<3.(4−13)(4−13)

                        ⇔2x<√3.⇔2x<3.

 Vậy phép biến đổi tương đương trong câu d là đúng. 

a ) Đúng 

b) Sai vì vế phải không có nghĩa 

c) Đúng 

d) Đúng

a) \(\sqrt{\left(x-3\right)^2}=9\Leftrightarrow\left|x-3\right|=9\)

\(\Leftrightarrow\orbr{\begin{cases}x-3=9\\x-3=-9\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=12\\x=-6\end{cases}}\)

Vậy ...

b) \(\sqrt{4x^2+4x+1}=6\Leftrightarrow\sqrt{\left(2x+1\right)^2}=6\)

\(\Leftrightarrow\left|2x+1\right|=6\Leftrightarrow\orbr{\begin{cases}2x+1=6\\2x+1=-6\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=\frac{5}{2}\\x=-\frac{7}{2}\end{cases}}\)

Vậy ...

a) x=12 hoặc x = -6

b) x = 5/2 hoặc x = - 7/2

a) $a{b}^2.\sqrt{\frac{3}{a^2{b}^4}}=a{b}^2.\frac{\sqrt{3}}{\sqrt{a^2{b}^4}}$

$=a{b}^2.\frac{\sqrt{3}}{\sqrt{a^2}.\sqrt{b^4}}=a{b}^2.\frac{\sqrt{3}}{|a|.|b^2|}$

$=a{b}^2.\frac{\sqrt{3}}{(-a).b^2}$ (Do $a<0$ nên $|a|=-a$ và $b\ne 0$ nên $b^2>0$ $\Rightarrow$  $\left|b^2\right|=b^2$)

$=-\sqrt{3}$.

b) $\sqrt{\frac{27(a-3{)}^2}{48}}=\sqrt{\frac{9(a-3{)}^2}{16}}$

$=\frac{\sqrt{9}.\sqrt{(a-3{)}^2}}{\sqrt{16}}=\frac{3.|a-3|}{4}$

$=\frac{3(a-3)}{4}$. 

(Do $a>3$ nên $|a-3|=a-3$)

c) $\sqrt{\frac{9+12a+4a^2}{b^2}}=\frac{\sqrt{3^2+\mathrm{2.3.2}a+(2a{)}^2}}{\sqrt{b^2}}$

$=\frac{\sqrt{(3+2a{)}^2}}{\sqrt{b^2}}=\frac{|3+2a|}{|b|}$
$=\frac{3+2a}{-b}=-\frac{2a+3}{b}$.

(Do $a\ge -1,5$ $\Rightarrow$ $3+2a\ge 0$ nên $|3+2a|=3+2a$ và $b<0$ nên $|b|=-b$)

d) $(a-b).\sqrt{\frac{ab}{(a-b{)}^2}}=(a-b).\frac{\sqrt{ab}}{\sqrt{(a-b{)}^2}}$

$=(a-b).\frac{\sqrt{ab}}{|a-b|}=(a-b).\frac{\sqrt{ab}}{-(a-b)}$

$=-\sqrt{ab}$.

(Do $a<b<0$ nên $|a-b|=-(a-b)$ và $ab>0$)

a) $a{b}^2.\sqrt{\frac{3}{a^2{b}^4}}=a{b}^2.\frac{\sqrt{3}}{\sqrt{a^2{b}^4}}$

$=a{b}^2.\frac{\sqrt{3}}{\sqrt{a^2}.\sqrt{b^4}}=a{b}^2.\frac{\sqrt{3}}{|a|.|b^2|}$

$=a{b}^2.\frac{\sqrt{3}}{(-a).b^2}$ (Do $a<0$ nên $|a|=-a$ và $b\ne 0$ nên $b^2>0$ $\Rightarrow$  $\left|b^2\right|=b^2$)

$=-\sqrt{3}$.

b) $\sqrt{\frac{27(a-3{)}^2}{48}}=\sqrt{\frac{9(a-3{)}^2}{16}}$

$=\frac{\sqrt{9}.\sqrt{(a-3{)}^2}}{\sqrt{16}}=\frac{3.|a-3|}{4}$

$=\frac{3(a-3)}{4}$. 

(Do $a>3$ nên $|a-3|=a-3$)

c) $\sqrt{\frac{9+12a+4a^2}{b^2}}=\frac{\sqrt{3^2+\mathrm{2.3.2}a+(2a{)}^2}}{\sqrt{b^2}}$

$=\frac{\sqrt{(3+2a{)}^2}}{\sqrt{b^2}}=\frac{|3+2a|}{|b|}$
$=\frac{3+2a}{-b}=-\frac{2a+3}{b}$.

(Do $a\ge -1,5$ $\Rightarrow$ $3+2a\ge 0$ nên $|3+2a|=3+2a$ và $b<0$ nên $|b|=-b$)

d) $(a-b).\sqrt{\frac{ab}{(a-b{)}^2}}=(a-b).\frac{\sqrt{ab}}{\sqrt{(a-b{)}^2}}$

$=(a-b).\frac{\sqrt{ab}}{|a-b|}=(a-b).\frac{\sqrt{ab}}{-(a-b)}$

$=-\sqrt{ab}$.

(Do $a<b<0$ nên $|a-b|=-(a-b)$ và $ab>0$)

Phương trình phản ứng thủy phân este CH₃COOCH₂CH₃ diễn ra như sau:

\(CH_3COOCH_2CH_3+NaOH\rightarrow CH_3COONa+C_2H_5OH\)

Sau phản ứng ta thu được muối và ancol, ancol có công thức là:\(C_2H_5OH\)

1.although he has a very important job, he isn't parularly well-paid
=> in spite of his very important job, he isn’t parularly well-paid.
2. although I had never seen her before , I recognized her from a photograph
=> despite having never seen her before, I recognized her from a photograph
3.she wasn't wearing the coat although it was quite cold
=> in spite of the cold, She wasn’t wearing the coat
4. I bought the dress though the dress is expensive
=> despite the fact that the dress is expensive,I bought the dress
5. although I didn't speak Chinese, I visited China
=> in spite of the fact that I didn't speak Chinese, I visited China
6.although the light was turning ,the room wasn't bring
=> despite the fact that the light was turning, the room wasn't bring
7. I didn't recognize her although I'd met her twice before
=> in spite of having met her twice before, I didn’t recognize her
8. we're not very good friends although we're known each other a long time
=> despite having known each other for a long time, We’re not very good friends
9. although Minh was still , he still came to the meeting
=> in spite of Minh's illness, he still came to the meeting
10. although he promised that he wouldn't be late, he didn't arrive until 9 o'clock
=> despite his promise not to be late, he didn’t arrive until 9 o’clock.
 

1. In spite of having a very important job, he isn't particularly well-paid.

2. Despite having never seen her before, I recognized her from a photograph.

3. In spite of the cold weather, she wasn't wearing the coat.

4. Despite not liking them very much, we thought we'd better invite them to the party.

5. In spite of not speaking the language, I managed to make myself understand.

6. Despite the heat, the room wasn't warm.

7. In spite of having met her twice before, I didn't recognize her.

8. Despite having known each other for a long time, we're not very good friends.

9. In spite of being ill, Minh still came to the meeting.

10. Despite promising that he wouldn't be late, he didn't arrive until 9 o'clock.

1. Although lion dancing is very popular in Viet Nam, my friend Anny doesn't enjoy it.

2. Bob always walks to work though he is living in the city.

3. Even though my house is near the beach, I rarely go swimming.

4. Although my brother is working in Hanoi, he comes home on every public holiday.

5. Though Paul is an Australian, he enjoys Vietnamese New year.

6. Even though most children go to see the firework show, Linh and Mai stay home watching TV.

7. Although Nick used to smoke, he seems to be in good health.

8. I couldn't sleep though I was tired.

9. Although Henry's friend is a millionaire, he hates spending money.

10. We couldn't get kets though we queued for an hour.

1. Although lion dancing is very popular in Viet Nam, my friend Anny doesn't enjoy it.

2. Bob always walks to work though he is living in the city.

3. Even though my house is near the beach, I rarely go swimming.

4. Although my brother is working in Hanoi, he comes home on every public holiday.

5. Though Paul is an Australian, he enjoys Vietnamese New year.

6. Even though most children go to see the firework show, Linh and Mai stay home watching TV.

7. Although Nick used to smoke, he seems to be in good health.

8. I couldn't sleep though I was tired.

9. Although Henry's friend is a millionaire, he hates spending money.

10. We couldn't get tickets though we queued for an hour.

1. A good doctor/ need/ know/ how/ whole body/ function/ and/ what/ people/ do/ maintain/ overall health.

=> A good doctor needs to know how to whole body functions and what people do to maintain overall health.

2. Doctors/ stay informed/ all/ latest breakthroughs/ medical field.

=> Doctor stays informed all people about the latest breakthroughs in the medical field.

3. doctor’s good manner/ make/ patients/ feel/ more comfortable/ appointments.

=>A doctor’s good manner makes patients feel more comfortable in appointments.

4. Doctors/ also explain/ what/ they/ doing/ and/ help/ patients/ treatments properly.

=>Doctors also explain to patients what they need to do and help patients treatments properly.

5. good doctor/ listen/ patients attentively/ and/ respond/ them carefully.

=> A good doctor always listen patients attentively and respond them carefully

Em đoán thế đó ạ :)))) 

1.A good doctor needs to know how the whole body functions and what people should do to maintain overall health.

2. Doctors should stay informed of all the latest breakthroughs in the medical field.

3. Doctor’s good manner makes patients feel more comfortable in appointments.

4. Doctors should also explain what they are doing and help patients with treatments properly.

5. A good doctor should listen to patients attentively and respond to them carefully.

* Vì đây là chương trình Anh lớp 9, chưa hiểu rõ. Có gì sai sót mong Admin thông cảm ạ *

Use the words or phrases given to write meaningful sentences about the most important qualities a person needs to become a good teacher.

1. teaching career/ demand/ love/ learning/ broad knowledge/ subject/ and/ classroom management techniques.

-> The teaching career demands a love of learning, a broad knowledge of subject, and classroom management techniques.

2. Teachers/ form/ strong relationships/ students/ and/ show/ they/look after/ students/ people.

-> Teachers should form strong relationships with their students and show that they look after students as people.

3. Teachers/ masters/ their subject matter/ and/ they/ present/ material/ enthusias manner.

-> Teachers are masters of their subject matter, and they present material in an enthusias manner.

4. They/ also/ present/ lessons/ clear and structured way/ and/ classrooms/ organized.

-> They also present lessons in a clear and structured way, and their  classrooms are organized. 

5. Teachers/ communicate/ frequently/ parents/ and/ they/ call/ student’s parent/ if/ they/ concerned/ a student.

-> Teachers communicate  frequently  with parents, and they call a student's parent if they are concerned about a student.

1.The teaching career demands a love of learning, a broad knowledge of subject, and classroom management techniques.
2.Teachers should form strong relationships with their students and show that they look after students as people. 
3. Teachers are masters of their subject matter, and they present material in an enthusiastic manner. 
4. They also present lessons in a clear and structured way, and their  classrooms are organized.  
5. Teachers communicate  frequently  with parents, and they call a student's parent if they are concerned about a student.

1. it's very important to eat healthy food.

2. let's have spaghetti anh pizza tonight.

3. the onion need to be peeled and sliced.

4. if you don't follow these safety ínstructions, you may get burn.

5 this is the first time my aunt has ever tasted shushi.

Complete the second sentence in each pair so that it has a similar meaning to the first sentence.

1. Eating healthy foods is very important.

→ It is very important to eat healthy foods

2. I suggest having spaghetti and pizza tonight.

→ Let's have spaghetti and pizza tonight!

3. You need to peel the onion and slice it.

→ The onion need to be peeled and sliced

4. Follow these safety instructions or you may get burnt.

→ If you follow these safety instructions , you maynot get burnt.

5. My aunt has never tasted sushi before.

→ This is the first  tasted sushi my aunt has eaten

* Vì đây là chương trình Anh lớp 9 nên chưa nắm rõ, có gì sai sót mong AD thông cảm ạ *

Complete the second sentence in each pair so that it has a similar meaning to the first sentence, using “you”.

1. Vegetarians don't eat meat.

→ If you're a vegetarian, you shouldn't eat meat.

2. People who live in a cold country don t hot weather.

→ If you live you won't hot weather.

3. Teachers have to work very hard.

→ If you're a teacher, you have to work very hard.

4. People who do a lot of exercise stay fit and healthy.

→ If you ​do a lot of exercise, you will stay fit and healthy.

5. Mechanics understand engines.

→ If you‟re a mechanic, you will understand engines.

6. People who read newspapers know what's happening in the world.

→ If you read newspapers, you will know what's happening in the world.

1......,you should not eat meat

2......in a cold country,you will not like hot weather

3.....,you can have to work very hard

4.....do alot of exercise,you can stay fit and healthy

5.... mechanic,you can understand engines

6.....read newspapers,you will know what is happening in the world