S=abc+bac+cab

=(100a+10b+c)+(100b+10a+c)+(100c+10a+b)

=(100a+10a+a)+(100b+10b+b)+(100c+10c+c)

=111a+111b+111c=111(a+b+c)=3.37.(a+b+c)

Giả sử S là SCP,mà 37 nguyên tố

=>S chia hết cho 37.Nhưng a+b+c ko chia hết cho 37

Vậy trái giả thiết

=>đpcm

Mẫu đơn đăng kí:
Tên:...P.T Linh Phương....................

Lớp:....8>9........

Link của nick dự thi: Góc học tập của phương linh | Học trực tuyến

/2Dùng What, Where, When, Who, Why, How, What time để hoàn tất các câu sau:

1. ....WHAT....... will they do tomorrow? I will do my homework.

2. ....WHO....... will go camping next Sunday? Nam and Quang will.

3. .....WHERE...... will we meet? We will meet at Lan's h0ouse.

4. ....WHAT TIME....... will you be back? I will be back at 8 O' clock.

5. .....HOW...... will she go to the zoo? She will go by bus.

6. ....WHEN....... will your father travel to Ha Noi? He 1will travel next week.

7. ....WHY....... will Nam go to bed early tonight? Bec.ause he will have a test tomorrow.

8. ...WHERE........ will Nam go to next summer vacation? I will go to Nha Trang.

I)Choose the underlined part among A,B,C orD that need correcting

1.he (did) the job (skillfull=>skillfully) and (the )employer was satisfied with (him)

2her mother (asked) her (not eat)=>not to eat fruits before (washing )(them)

3Tim (should) (spend) more (in=>on) (spanish) pronunciation

4Ba always( gets )excillent (grades) (because) he studies (hardly=>hard)

5we (shouldn't=>should) use dictionaries (to find out)( how) to( pronounce) english words

-504 đó bn

1 phút suy nghĩ = 1 năm không nằm