CÂU TRL LÀ  NHA E , CHÚC EM HỌC GIỎI

8 em nhé

8 nha em xin k em ới
 

: ( 9/4 + 16/5 + 25/6 ) - ( 5/4 - 14/5 + 47/8 ) =0. 78125

\(\left(\frac{9}{4}+\frac{16}{5}+\frac{25}{6}\right)-\left(\frac{5}{4}-\frac{14}{5}+\frac{47}{8}\right)\)

\(=\frac{9}{4}+\frac{16}{5}+\frac{25}{6}-\frac{5}{4}+\frac{14}{5}-\frac{47}{8}\)

\(=\left(\frac{9}{4}-\frac{5}{4}\right)+\left(\frac{16}{5}+\frac{14}{5}\right)+\left(\frac{25}{6}-\frac{47}{8}\right)\)

\(=1+6-\frac{41}{24}\)

\(=7-\frac{41}{24}=\frac{127}{24}\)

(\(\frac{9}{4}+\frac{16}{5}+\frac{25}{6}\)) -(\(\frac{5}{4}-\frac{14}{5}+\frac{47}{8}\))

=\(\frac{9}{4}+\frac{16}{5}+\frac{25}{6}-\frac{5}{4}+\frac{14}{5}-\frac{47}{8}\)

=\(\frac{9-5}{4}+\frac{16+14}{5}+\frac{25}{6}-\frac{47}{8}\)

= 1 + 6+\(\frac{200-282}{48}\)

=\(\frac{336-82}{48}\)

=\(\frac{254}{48}\)

=\(\frac{127}{24}\)

câu 5: 

x=3,6

y=6,4

câu 6: chụp lại đề

câu 7:

a)ĐKXĐ: \(x\ge0\)

\(3\sqrt{x}=\sqrt{12}\\ \Rightarrow9x=12\\ \Rightarrow x=\dfrac{4}{3}\)

b) ĐKXĐ: \(x\ge6\)

\(\sqrt{x-6}=3\\ \Rightarrow x-6=9\\ \Rightarrow x=15\)

Câu 5: 

Áp dụng định lý Pi-ta-go ta có:

\(AB^2+AC^2=BC^2\\ \Rightarrow BC=\sqrt{6^2+8^2}\\ \Rightarrow BC=10\)

Áp dụng HTL ta có: \(x.BC=AB^2\Rightarrow x.10=6^2\Rightarrow x=3,6\)

Áp dụng HTL ta có: \(x.BC=AC^2\Rightarrow x.10=8^2\Rightarrow x=6,4\)

1. $(-5)^20$ > 0 do đây là lũy thừa có số mũ chẵn, cơ số âm; $(-8)^7$ < 0 do đây là lũy thừa có số mũ lẻ, cơ số ấm. Do đó $$(-5)^20$>(-8)^7$.

2. $2^20 +\dfrac{1}{2^21} + 1 - (2^19 +\dfrac{1}{2^20} + 1)  = (2^20 - 2^19) + (\dfrac{1}{2^21} - \dfrac{1}{2^20}) + (1 - 1) = 2^19.(2-1) + (\dfrac{1}{2^21} - \dfrac{1}{2^20} = 2^19 - \dfrac{1}{2^20}  + \dfrac{1}{2^21} > 0$.

9: =-32+40+56-28

=8+28

=36

7: =-10+15-28+14

=5-14

=-9

1. Tầng = floor
2. Đường phố = Street
3. Quê hương = hometown
4. Vùng quê = countryside
5. Đất nước = country
6. Yên bình = Peaceful
7. Đông đúc = Crowded
8. Bận rộn = Busy

Dịch nghĩa hả em ?

Mấy anh chị giúp em với ạ

3. I began living there in 2010..

→ I have..been living there since 2010...

4. They started to play football when they were 8 years old.

→They have.played football since they were 8 years old...

5. She began getting married 20 years ago.

→She has..been getting married for 20 years.....

6. He began to be a teacher 23 years ago.

=> He has been to be a teacher for 23 years

7. I haven't seen him since Christmas. →

The last time..I saw him was on Christmas day....

8. I haven't seen him since I left school.

→ The last time..I saw him when I left school.....

9. I haven't seen him for 8 years.

→The last time..I saw him ...was 8 days ago...

10. They haven't worked for this company since 1992.

→ The last time...they worked for this company was on 1992.....

11. They haven't worked for this company since they moved their houses →The last time...they worked for this company when they moved theire houses.....

12. They haven't worked for this company for 10 years.

→The last time...they worked for this company was 10 years ago .....

13. We have not studied in this school for nearly 3 years.

→The last time...we studied in this school was nearly 3 years ago....

14. We have not studied in this school since we were in grade 10.

→The last time...we studied in this school when we were in grade 10....

15. We have not studied in this school since last year.

→The last time...we studied in this school was on last year....

16. I got married her in 2000.

→I have..married her since 2000.

17.I got married her when I was 30 years old.

=>I have..married her since I was 30 years old..

18. I got married her 12 years ago.

=> I have.married her for 12 years..

19. I graduated from high school when I was 18 years old.

=>I have.graduated from high school since I was 18 years old...

20. We graduated from high school in 1999.

→We have.graduated from high school since 1999....

21. We graduated from high school 25 years ago.

=>We have..graduated from high school for 25 years..

22. I haven't seen Bob since I was in Ho Chi Minh City.

→ I last saw Bob when I was in Ho Chi Minh City

23. They've been using robots in this factory for ten years.

→ They started to use robots in this factory 10 years ago

24. Doctors and scientists been to fight against CORONA VIRUS two years ago.

→Doctors and scientists have.. been fighting against Corona virus for two years

25. We started learning in this school when we were 15 years old.

→ We have been learning in this school since we were 15 years old

26. Mary began to work in this company 5 years ago.

→Mary has worked in this company for 5 years

27. He last time she visited her home town when she was 25.

→ She hasn't visited her home town  since she was 25

28. He last had his eyes tested 6 months ago.

→ He hasn't had his eyes tested for 6 months

có nha em

Tham khảo:

Mùa xuân 1793 = 21 - 1 - 1793