cho A= 1 +3+32 +......+ 319 +320
chứng tỏ A chia hết cho 13
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(x\times\dfrac{5}{7}-3=18\)
\(x\times\dfrac{5}{7}=18+3\)
\(x\times\dfrac{5}{7}=21\)
\(x=21:\dfrac{5}{7}\)
\(x=\dfrac{147}{5}\)
X x 5/7 - 3 = 18
X x 5/7 = 18 + 3
X x 5/7 =21
X =21 : 5/7
X =147/5
2.He doesn't know he boat may take a trip around the island.
3.Phuong, Tuan and Hoa may build sandcastles on the beach.
4.My family and I will swim in the sea.
5.They'll be at the seaside on sunday.
2.He doesn't know he boat may take a trip around the island.
3.Phuong, Tuan and Hoa may build sandcastles on the beach.
4.My family and I will swim in the sea.
5.They'll be at the seaside on sunday.