Chứng minh công thức tính điện trở tương đương của đoạn mạch gồm hai điện trở R1, R2 mắc song song: $\frac{1}{Rtđ}$ = $\frac{1}{R1}$ + $\frac{1}{R2}$ từ đó suy ra Rtđ= $\frac{R1.R2}{R1+R2}$

môn này là giáo dục quốc phòng lớp 11 ạ,do không có môn này nên mình để tạm gdcd mọi người giúp mình câu này với xíu mình nộp rồi bài: nêu các quan điểm của đồng bào về bảo vệ biên giới quốc gia

TOPIC: DIRECT SPEECH AND INDIRECT SPEECH 35. “Tom had an accident last week, but he wasn't injured," said Mary. A. Mary said Tom had an accident last week but he wasn't injured. B. Mary said Tom had had an accident last week but he wasn't injured. C. Mary said Tom had an accident the last week but he hadn't been injured. D. Mary said Tom had had an accident the week before but he hadn't been injured. 36. “I don't know what Fred is doing," said my sister. A. My sister said that she didn't know what Fred was doing. B. My sister said she doesn't know what Fred is doing. C. My sister said that I don't know what Fred is doing. D. My sister said that she hasn't known what Fred was doing 37. I suggested that he should paint the house light blue. A. "Shall we painted the house light blue?" I said to him. B. "How about to paint the house light blue?" I said to him. C. "Let's paint the house light blue," I said to him. D. "Why don't you paint the house light blue?" I said to him. 38 . He invited me to have dinner with him. A. "Would you like to have dinner with me?" he said. B. "Do you like having dinner with me?" he said. C. "Would you like dinner with me?" said he. D. "Will you like to have dinner with me?" said he. 39. They wanted to know where I came from. A. "We want to know where do you come from," they said. B. "Where did you come from?" they asked. C. "Where do you come from?" asked they. D. "We wanted to know where I came from," they said. 40 . He reminded me to buy him some stamps. A. "Don't forget to buy me some stamps," he said. B. "Remember buying me some stamps," said he. C. "Remind to buy me some stamps," said he. D. "Don't deny buying me some stamps.," he said. 41. "I'll definitely return it to you tomorrow, " John said. A. John said that he'll return it to me the next day. B. John promised to return it to me the next day. C. John told that he'll return it to me the next day. D. John decided to return it to me next day. 42. "Shall I carry your suitcase, Mary? " said Peter. A. Peter promised to carry Mary's suitcase. B. Peter decided to carry Mary's suitcase. C. Peter wanted to carry Mary's suitcase. D. Peter offered to carry Mary's suitcase

Mn ơi giúp e vs ạ E cảm ơn mn rất nhìu

Cho tam giác ABC. Qua đỉnh A vẽ đường thẳng a song song với BC, qua đỉnh B vẽ đường thẳng b song song vs AC. Hỏi vẽ đc mấy đường thẳng a, mấy đường thẳng b, vì sao

Viết đoạn văn (6-8 câu) với chủ đề " người thân yêu của em" có sử dụng đại từ, quan hệ từ. Gạch chân, chú thích đại từ và quan hệ từ đó. Viết đoạn văn (6-8 câu) với chủ đề " người thân yêu của em" có sử dụng đại từ, quan hệ từ. Gạch chân, chú thích đại từ và quan hệ từ đó.

sin x + √3 cos x = -2 (giải giúp em với ạ e cảm ơn)

giải hộ mình nhé Ai nhanh mình cho nhất

viết một đoạn văn về gia đình có sử dụng phép nói giảm nói tránh, nói về ba mẹ ý mọi người, giúp em với

Việt Nam và mĩ có mối quan hệ ngoại giao như thế nào