Vẽ Oz // Ax

=> \(\widehat{xAO}=\widehat{AOz}\left(soletrong\right)=50^0\)

Ta có: \(\widehat{AOz}+\widehat{zOB}=\widehat{AOB}\)

hay \(50^0+\widehat{zOB}=80^0\)

\(\widehat{zOB}=80^0-50^0\)

=> \(\widehat{zOB}=30^0\)

Vì Ax // Oz

mà Ax // By

=> Oz // By

=> \(\widehat{OBy}=\widehat{zOB}\left(soletrong\right)=30^0\)

=> \(\widehat{OBy}=30^0\)

Sách Tập 1 hay Tập 2 vậy bn?

tập 1 đó bn

chịu,ko bt lm chx xem đến mấy cái bài đó

Mk cần gấp nha cảm ơn mn

a) 6,21 : 4,5 + 31,5 : 4,5 - 7,74 : 4,5

= (6,21 + 31,5 - 7,74) : 4,5

= 29,97 : 4,5

= 6,66

tiếp câu b đi

tui cũng hỏi hai câu này

Chuyển các câu sau sang bị động

1.My father waters this flower every morning.

==> This flower is watered (by my father) every morning.

2.John invited Fiona to his birthday party last night.

==> Fiona was invented to John’s birthday party last month.

3.Her mother is preparing the dinner in the kitchen.

==> The dinner is being prepared (by her mother) in the kitchen.

4.We should clean our teeth twice a day.

==> Our teeth should be cleaned twice a day.

5.Our teachers have explained the English grammar.

==> The English grammar has been explained (by our teacher).

6.Some drunk drivers caused the accident in this city.

==> The accident was caused in this city (by some drunk drivers).

7.Tom will visit his parents next month.

==> Tom’s parents will be visited (by him) next month.

8.The manager didn’t phone the secretary this morning.

==> The secretary wasn’t phoned (by the manager) this morning.

9.Did Mary this beautiful dress?

==> Was this beautiful dress bought by Mary?

10.I won’t hang these old pictures in the living room.

==> These old pictures won’t be hung in the living room(by me).

11.The German didn’t build this factory during the Second World War.

==> This factory wasn’t built (by the Greens) during the Second World War.

12.The Greens are going to paint this house and these cars for Christmas Day.

==> This house and these cars are going to be painted for Christmas day by the Greens.

13. Ann had fed the cats before she went to the cinema.

==> The cats had been fed (by Ann) before she went to the cinema.

14.The students have discussed the pollution problems since last week.

==> The pollution problems have been discussed (by the students) since last week.

15.Have the thieves stolen the most valuable painting in the national museum?

==> Has the most valuable painting in the national museum been stolen (by the thieves)?

16.Some people will interview the new president on TV.

==> The new president will be interviewed on TV (by some people).

17.How many languages do they speak in Canada?

==> How many languages are spoken in Canada(by them)?

18.Are you going to repair those shoes?

==> Are those shoes going to be repaired ?

19.He has broken his nose in a football match.

==> His nose has been broken in a football match(by him).

20.Have you finished the above sentences?

==> Have above sentences been finished ?

Chúc pạn hok tốt!!!

viết đầu bài ra giải hộ cho

cho mình hỏi có phải sách vnen không vậy?

Theo đề bài sau bốn lần căng dây đo liên tiếp thì khoảng cách giữa hai đầu dây và mép tường còn lại bằng 1515 độ dài sợi dây, nên chiều rộng lớp học sẽ là độ dài của bốn lần sợi dây và 1515 độ dài sợ dây đó.

(chiều rộng lớp học) = (độ dài sau 4 lần đo) + (1/5 độ dài sợi dây)

Chiều dài của 1/5 sợi dây là: 1,25 . 1/5 = 0,25 m

Chiều rộng lớp học là: 4.1,25 + 0,25 = 5,25 m

Vậy chiều rộng lớp học là 5,25 m.