Ta có: (2n+5)²-25=(2n+5)²-5²=(2n+5-5).(2n+5+5)=2n.(2n+10)=2.n.2.(n+5)

=4.n.(n+5) chia hết cho 4

=>(2n+5)²-25 chia hết cho 4

nếu họ nguyễn thì chỉ có thể là Nguyễn Đình Dũng thui 

Bài 1: Change these sentences into passive

1. People wear glasses

=>................Glasses are worn ................

2. The children drinks milk

=>.................Milk is drunk by the children....................

3. Our children keep a cat and a dog as pets

=>.................A cat and A dog are kept as pets by our children.....................

4. A rooster does not lay eggs

=>....................Eggs are not laid by a rooster......................

5. Sheep give the wool

=>..............The wool is given by sheeep...................

thế còn King Kong

Nguyễn Ngọc Sáng

Nguyễn Trung Hiếu

Ngô Tuấn Vũ

Nguyễn Văn Tân

Lê Chí Cường

Nguyễn Tuấn Tài

thì sao

Bài 2: Change these sentences into passive

1. My mother did not serve the dinner

=>.......................The dinner wasn't served by my mother...............................

2. They left hats and coats here

=>........................Hats and coats are left here (by them)........................

3. They can not hold the meeting in that room

=>............The meeting can not be hold in that room (by them).....................

p/s: trong ngoặc thì có hoặc không...

1 considered/d/ rescued/d/ pulled/d/ roughed/t/

2 produced/t/ arranged/d/ checked/t/ fixed/t/

3 caused/d/ examined/d/ operated/id/ advised/d/

Ta thấy: 234=2.3².13

              180=2².3².5

=>ƯCLN(234,180)=2.3²=18

A. Who does he live with? - His sister/He lives with his sister.

B. How do you go to school everyday?-By bicycle/I go to school by bike everyday.

C. What do you do? - A student/I'm a student.

Ta có:Ư(45)=(1,3,5,9,15,45)

=>Có 2 ước tự nhiên có 2 chữ số là Ư(45)

It will snow in the mountains tomorrow evening.