Biết Nm=23,4382.10-27kg. Khối lượng của nitơ theo đơn vịcacbon gần với giá trịnào nhất (1u = 1,6605. 10-27kg

$$\begin{gathered} giải pt \\ cot(2x+\frac{\mathrm{\pi }}{7})=-\sqrt{3} \\ cot(-4x+\frac{\mathrm{\pi }}{12})=\frac{1}{\sqrt{3}} \end{gathered}$$

gấp nữa

Choose A, B, C or D below to complete the passage.

My weekends are fast and exciting. My weekdays are fast and domestic! I…(1).............……two sons, Dylan, 7, and Dakota, 5. Every morning I …(2).............……one hour before them, at 6.00, and I…(3).............…… to the gym. I…(4).............……home and I have breakfast, then I …(5).............…… them to school. On Mondays I always…(6).............… I buy all the food for the week. I often …(7).............……dinner in the evenings, but not every day because I don’t …(8).............……cooking. Fortunately, my husband, Don, likes cooking. On Tuesdays and Thursdays I…(9).............……my father. He …(10).............…… on the next block. Every afternoon I …(11).............…… the kids from school. In the evenings Don and I usually relax but sometimes we visit friends. We never …(12).............…… on Friday evenings because I start work so early on Saturdays.

1. A. want B. like C. love D. have

2. A. get up B. sleep C. eat D. exercise

3. A. have B. use C. go D. start

4. A. walk B. come C. run to D. come to

5. A. take B. pick up C. am talking D. talking

6. A. go market B. go shopping C. go supermarket D. go shop

7. A. buy B. have C. eat D. cook

8. A. like B. hate C. dislike D. want

9. A. see B. meet C. visit D. talk

10. A. lives B. living C. come D. stay

11. A. take B. bring C. carry D. pick up

12. A. go out B. stay C. eat D. talk

Cho tập hợp A=[ -2;1] và B = (0: 8). Tập A hợp B là tập nào? 

Ấn độ thời phong kiến

tên vương triều

người thành lập

thời gian tồn tại

chính sách cái trị

1 It often ( not rain ) ................ in the dry-season

2 Lan ( brush ) .............. herteeth 3 times a day so they ............. veri white and beautitul

3 ................ She usually .............. herhomework before going to play tennis ?

4 My son ( play ) ................. games with his sister on computer now

1+3x+3x^2+x^2 Phân tích đa thức thành nhân tử

Gấp nha mn

1. It’s good to meet people from.............parts of the country. (different/ same/ difficult/ another)

2. This bicycle is broken down. It is in need of............. (repair/ repaired/ repairs/ repairing)

3. Many people do not like the idea of.............on animals (experiment/ experiments/ test/ example)

4. Children.............ten must pay full price for the ticket. (under/ below/ over/ on)

5. The shoes alone.............300.000 VND. (price/ prices/ costs/ cost)

6. Most students face the.............of stress because of heavy programs. (difficult/ problem/ different/ difference)

7. Water freezes at.............degree Celsius. (a hundred/ ninety/ zero/ high)

8. He must.............this fault word before you send it to your teacher. (erase/ make/ write/ do)

9. He takes no pleasure in his sport. “pleasure” means ….. (dislike/ hatred/ happiness/ sadness)

10. World Cup has famous.............in the world. (events/ event/ problem/ thing)

11. I’m not really.............sport. (interested in/ interesting at/ interesting in/ interested at)

12. To Hoai is the best.............of teenagers. (policeman/ teacher/ author/ doctor)

13. Before my mother go to work, she often comes to read the gas.............in her motor. (meter / fuel/ box/ can)

14. In summer, some places have.............in the 40s. (weather/ temperature/ temperatures/ degree)

15. The “b” in lamb is............. (not pronounced/ say/ hear / read)

16. You can find your favorite song in this............. (phone directory/ students book/ songbook/ dictionary)

17. In exercise 4, X and Y in the.............are unknown. (equation/ problem/ place/ space)

18. You can do this exercise by............. (machine/ calculator/ calculation/ electric machine)

19. The.............is round. (egg/ map/ globe/ ruler)

20. Atlas is a book of............. (colors/ drawing/ lines/ map)

21. Cut the sandwiches into............. (triangles/ colors/ circles/ things)

22. She walks the horse.............in a circle. (round/ ahead/ straight/ right)

23. These boys are playing............. (televisions/ marbles/ books/ computers)

24. He.............into the dark point in the room. (thinks/ looks / smiles/ stares)

25. He knew I am a(n).............person and would get things done. (energetic/ lazy/ hard/ amusing)

26. The full-time.............is 1-1. (point/ grade/ score/ mark)

27. We use a.............cassette to play our dance in the picnic. (easy/ stereo/ big/ portable)

28. “Romeo and Juliet” is the.............I like reading best. (book/ film/ play/ dance)

29. A shopkeeper sends me a.............of sweets. (can/ glass/ packet/ bowl)

30. My brother ............. . our room before our mother comes back.

(is breaking/ is sweeping/ is singing/ is dancing)

31. She gives me.............of candy. (cup/ glass/ bowl/ box)

32. We only meet each other by writing letters. We are............. (pen pal/ friend/ family/ classmate)

33. In playing basketball people often say:

a. make a score b. shooting some hoops

c. fair play d. (they say nothing)

34. These girls.............in the playground. (are flying/ are crying/ are studying/ are skipping)

35. We tied his hands together with............. (rope/ band/ paper/ hair)

36. Badminton is a(n).............game. (outdoor/ office/ indoor/ company)

37. This year, how many countries.............in the World Cup? (take part/ look/ enter/ come)

38. I hope you don’t mind the.............in class. (accident/ noise/ love/ loudness)

39. His parents raise chicken in the back............. (yard/ space/ ground/ house)

40. The.............way to get a high score is study hard. (famous/ best/ unpopular/ common)

Cho tập hợp A = ( 2; 5 ], B = (3; 8). Tập hợp A \ B là: 

2^(x+1).3^x-6^x=216

Một con tàu của hợp tác xã thủy sản đánh bắt được 6 tấn 930kg cá gồm cá chim, cá đuối và cá thu. Khối lượng cá thu gấp đôi khối lượng cá chim và cá đuối, khối lượng cá đuối bằng 3/4 khối lượng cá chim. Tính khối lượng mỗi loài cá.

Tổng số cây trồng được của 3 lớp 7A,7B,7C là 370 cây. Số cây trồng được của 3 lớp 7A,B,7C lần lượt tỉ lệ với $\frac{5}{4}$:$\frac{3}{2}$:$\frac{15}{8}$.Hỏi mỗi lớp trồng được bao nhiêu cây?

Ai giúp em với , cảm ơn rất nhiều ạ!

Hiện nay mẹ của Quyên 26 tuổi và gấp đôi tổng số tuổi của hai chị em Quyên. Hỏi khi mẹ 32 tuổi thì tuổi của mỗi chị em Quyên là bao nhiêu? Biết Quyên kém chị 3 tuổi.

Tìm hai số x, y biết tổng hai số bằng 275 đơn vị và tỷ lệ giữa x và y là 7/4 ?