\(a,n^2+3⋮n-1\)

\(\Rightarrow n\left(n-1\right)+3+n⋮n-1\)

\(\Rightarrow n+3⋮n-1\)

\(\Rightarrow n-1+4⋮n-1\)

\(\Rightarrow4⋮n-1\)

...........You make the table, If i make the table, it will spent my times

That is answer:6 intergers

\(b,A=4+2^2+2^3+...+2^{20}\)

Put \(B=2^2+2^3+...+2^{20}\)

\(\Rightarrow2B=2^3+2^4+...+2^{21}\)

\(\Rightarrow2B-B=\left(2^3+2^4+...+2^{21}\right)-\left(2^2+2^3+...+2^{20}\right)\)\(\Rightarrow B=2^{21}-4\)

`\(\Rightarrow A=2^{21}-4+4=2^{21}\)

c,Consider the range of values

Put B=2.4.6.8...48

Because of B=2.4.6...10....48

=> The last digit of B is 0

Put C=1.3.5...49

Because of C= 1.3.5...49

=> The last digit of C is 5

=> B-C will have the last digit is 5

=> A have the last digit ís 5

I don't have anything planned. and  I'll probably just stay at home and relax.

There is a small pond from Lam house.

~ Học tốt ~

There / be / small / pond / front / lam / house

=> There will be a small pond in front of Lam's house.

The fall is the season ......... fruits

A . on      B. of       C. at        D. in

The fall is the season ......... fruits

A . on      B. of       C. at        D. in

trả lời

đáp án là b.short

hok tốt

Trả lời:

B. short

Học tốt ~

The day is short and the .............is long.

A . Afternoon        B . Morning         C . Dinner         D . Night

Trả lời:

D. Night

Học tốt ~

1, weather cool -> cool weather

2, two -> twice

3, plays -> play

4, some -> any

5, rice fried -> fried rice

6, is -> are

7, aren't -> don't

8, always can -> can always

9, usually you -> you usually

10, subjects -> subject

Chúc bn hok tốt

1, weather cool -> cool weather

2, two -> twice

3, plays -> play

4, some -> any

5, rice fried -> fried rice

6, is -> are

7, aren't -> don't

8, always can -> can always

9, usually you -> you usually

10, subjects -> subject

Chúc bn hok tốt

Trl:

Tôi nghĩ bạn đã hỏi cô Gul.

Mk ko chắc nx , lên google dịch ik bn

Trả lời :

Tôi nghĩ bạn đã hỏi cô Gul

~ Hok tốt ~

a) Do you often exercise mor ning in the summer?
- Yes, I exercise regularly in the summer

b) Do you exercise regularly in the winter?
- No, I don't often exercise in the winter

c) do you take a cold shower in the winter? If yes, how often?
- I don't take a cold shower in winter

d) Do you run every day in the summer?
- Yes, I have jogging in the summer

e) Do you run every day in the winter?
- No, I'm not jogging in the winter
f) do you run in the winter? how long?
- No, I'm not jogging in the winter
g) do you run in the summer? how long?
- Yes, I have jogging in the summer. Each time runs for about 30 minutes
h) do you do aerobics? If yes, how often in summer and often in winter?
- No, I don't exercise in rhythm

Correct form of the verbs in brackets:

1. There are lots of children in the school yard yesterday. 

2. They are listening to music now. They aren't watching TV. 

3. Look! The sun is shining brightly at the moment. 

4. Is there a clock in your classroom? 

5. We wash dirty clothes every day, but we aren't washing them now. 

6. His mother goes to the supermarket every Sunday, but my mother isn't going there this morning. 

7. She s sweets when she was a kid. 

8. I always have breakfast at 6 o'clock but the morning I am having it at 5:30. 

9. Who is waiting for me? My friend is waiting for me. 

10. He lived in the countryside two years ago. Now he is living in the city. 

11. Who do you live with? I live with my parents and sister. 

12. Ha comes to school with her sister every day but yesterday she went with her best friend and now she is going with a school mate. 

P/s: hok chắc :<

1) are                             5 wash/are washing             9 is waiting/live

2 are listening                 6 goes/isn't going              10 lived/is living

3 is shining                     7                                    11 do...live

4 Is đứng đầu câu          8 have/am having                12 comes/went/is going