a: Xét tứ giác AEHF có 

\(\widehat{AEH}=\widehat{AFH}=\widehat{FAE}=90^0\)

Do đó: AEHF là hình chữ nhật

2. Can you remember to see my keys? I can't find them.

3. Oh no! I forgot to send my mom a birthday card! She'll be ready upset.

4. I would have arrived earlier, but I had to stop to get some gas for my car.

5. I try to do some exercise every day, but I often can't find the time.

6. You can forget to go out tonight! You haven't done your homework.

7. Please stop talking for a minute and just listen to me.

8. He's been trying to learn to drive for years but keeps failing the test.

9. I've stopped using my car so much and walked as much as I can.

10. You must remember to visit Aunt Anna when you're in town.

 11. I was really hot, so I tried to splash my face with cold water.

12. Remember to turn off your phone before you enter. 

13. I don't remember meeting her at your wedding at all.

14. She's not interested in you, so you can forget to ask her out.

15. I felt sick so I tried to drink some ginger tea.

16. My children never remember putting the milk back in the refrigerator.

17. I stopped drinking so much caffeine and now I feel much better.

18. We've been trying to get the car out all morning, but the snow is just too deep.

19. We'll have to stop to buy him a present on the way to the party.

20. I didn't remember sending that email before I left the office.

21. I think I forgot to turn off the iron before I left.

22. Why don't you stop playing on your computer and go outside for some fresh air?

23. Could you try to remember people's names, please? It's really rude to keep forgetting.

24. If he's not answering his telephone, you could try to get in touch with him by email.

phần con lại cj gửi nhé

3:

a: Xét ΔACH vuông tại H và ΔBCA vuông tại A có

góc C chung

=>ΔACH đồng dạng vơi ΔBCA

b: Xét ΔABC vuông tại A có AH là đường cao

nên AH^2=HB*HC

e) thu gọn : -\(\dfrac{4b^{14}c^5a^{17}}{3}\)

Bậc : 36

phần biến : \(a^{17}b^{14}c^5\)

f) thu gọn : \(\dfrac{a^{12}b^9}{256}\)

bậc : 21

phần biến : \(a^{12}b^9\)

-14,14

ƯC(-14,28) = {1;-1;2;-2;7;-7;14;-14}

Chúc bạn học tốt 

Cảm ơn nhiều nhé 

=1 nha bạn

E muốn bt cách lm bài cơ

Số số hạng của A là:

( 100 - 3 ) : 2 + 1 = .... ( tự tính lấy nhé )

Tổng của A là:

( 3 + 100 ) x (kết quả của số số hạng) : 2

=> Đ/s:

1. C 
2. B 
3. A 
4. C 
5. C 
6. B 
7. B 
8. A 

a: =58(57+150-125)=58x82=4756

b: \(=9\cdot5-4\cdot7+83=45-28+83=100\)

c: =(2019-2019)+(-247-53)=-300

d: \(=13\cdot70-50\cdot\left[10:2+8\right]=910-50\cdot13=910-650=260\)

\(a,=58.\left(57+150-125\right)\\ =58.82=4756\\ b,=9.5-4.7+83.1\\ =45-28+83=100\)

\(a.4756\\ b.100\\ c.-300\\ d.260\)