tra loi nhanh giup mk nha
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
dãy số trên có số số hạng là:
(160-2):2 +1=80
dãy số trên bằng:
(160+1).80:2=6440
The most impressive change is in education. Recently, there are more schools rebuilt nearby and they are all better equipped. This summer, my hometown friends and I enjoy reading different kinds of books and comics in the new library. This change makes my stay here a lot more enjoyable.
Means of communication is the second big change I can see in the area. In the past, the common way to contact somebody faraway was to write letters by hand. Nowadays, thanks to mobile phones and even social networks, the locals can keep in touch more easily.
However, the negative change in the environment is something I dislike. Vast paddy fields where the children used to fly kites no longer exist. Instead, a new industrial zone appears. Worse, factories in the zone are polluting the river and make it too dirty for us to swim in.
My village has a lot of changes. Before anyone used oil lamps instead of electric lights as now, this road from my school to the house had bulbs along the road not as dark as before. The fields I am now also big, spacious and beautiful. than before.
So chia het cho 63 la so chia het cho 7 va 9 . Vay tong cac chu so cua so do la :
2017 x 7 = 14119
Ta thay : 14119 : 9 du 7 vay so do : 9 du 7 .
Vi so do duoc viet voi 2017 chu so 7 nen so do chia het cho 7 .
Vi so do chia 9 du 7 ; chia het cho 7 nen ta bot so do di 7 dv thi so do chia het cho 9 hay chia het cho 63 . Vay ban dau so do chia 63 du 7 .
gọi số đó là 77777...777 ( 2017 chữ số 7)=A
số đó muốn chia hết cho 63 thì phải chia hết cho 7 và 9
vì A chia 7 đc 111...111(2017 chữ số 1)
và tổng các chữ số là 7*2017=14119 (chia cho 9 dư 7)
nên số đó chia cho 63 dư 7 (đpcm)
(bài cực chuẩn đó)
tra loi mk hanh là sao ?????/
Hỏi thì phải có dấu chứ, hỏi ko ai hiểu thì đừng đăng
thank you , ban tra loi ho mik cac bai khac duoc khong , please