cho mình hỏi câu a bài 3 bạn làm sao z

30  k nha

1 người làm cần số ngày là :

        11 * 63 = 693 ( ngày )

Số người sau khi thêm là :

        693 : 7 = 99 ( người )

Cần thêm số người là :

        99 - 63 = 36 ( người )

            Đáp số : 36 người

31 There are four seasons in ...... ( the south/ central/ the north )

32 Where is HCM city ? - it is in ...... of Viet Nam ( thd south/ central/ the north )

33 You can avoid ..... when you are careful ( helmets / accidents / motorbikes )

34 Do not ...... down the staircase ( ride / swing / glide )

35 We went to Ha noi ...... train ( with / on / by )

36 ...... play with a sharp tool such as a knife ( does not / did not / do not )

37 Get your sister to ...... A helmet when she is on a bike or motorbike ( wear / ride / glide )

38 ...... let your younger brother or sister play with lighters ( always / sometimes / never )

39 Her ..... house will be in the countryside ( dream / small / beautiful )

40 My favourite detective ..... is Case Close ( character / story / book )

a ) 16 , 80 , 176

theo đề ta có :

16 = 2⁴

80 = 2⁴.5

176 = 2⁴.11

ƯCLN (16 , 80 , 176 ) = 2⁴

b ) 18 , 30 , 77 

theo đề ta có : 

18 = 2 . 3² . 1

30 = 2 . 3 . 5 . 1

77 = 7 . 11 . 1

ƯCLN (18 , 30 , 77 ): 1.1.1=1

8km417 = 8,417 km

7km5m =7,005km

4km28m =4,028km

216m =0,216 km

k nha

daoloananh

a) S + 02 mũi tên SO2

b) 3Fe + 2O2 mũi tên Fe3O4

c) 4P + O2 mũi tên 2P2O5

d) CH4 + 2O2 mũi tên CO2 + 2H2O

21 It will be a cottage..... the sea ( in/ by/ at)

22 I have got a backache .You should not ..... ( eat sweets/ drink medicine/ carry heavy thing)

23 We often ..... sightseeing in our free time ( watch/ go/ have)

24 Which city is ......, Da Nang or Ha An ?( small/ smallest/ smaller)

25 There are four ..... in our country ( weather/ months/ seasons)

26 I often ..... football matches on TV ( see/ listen/ watch)

27 I like Conan Kudo . He is ..... ( beautiful/ talented/ tricky)

28 It is very hot in .......( summer/ autumn/ spring/ winter)

29 How ..... is it form here to your hometown ?( old/ long/ far)

30 Do not play with ..... You may get a burn ( knife/ cat/ lighter)