Gọi giao điểm của CF với BE là M, giao điểm của EF với CD là N.
 

Theo tính chất góc ngoài của tam giác, ta có:
 

BMF^=B^+C1^;BMF^=F^+E1^
 

suy ra B^+C1^=F^+E1^ (1)
 

Tương tự D^+E2^=F^+C2^ (2)
 

Mặt khác, theo giả thiết thì: C1^=C2^,E1^=E2^ (3)
 

Từ (1) (2) và (3) suy ra
 

2F^=B^+D^ nên F^=B^+D^2
 

hay CFE^=ABC^+ADE^2

100 bại vy sai rùi 

số thích hợp là 9144

x=1

y=4

X. Rewrite the following sentences using the given words so that it has similar meaning:
1. Tom is the younger of the two brothers?
-> Tom has ....two elder brothers....
2. Mexico city is bigger than New York city.
-> New York city is not as ....big as Mexico city....
3. Why isn’t the car working now?
-> What’s ....wrong with the car....?
4. Why don’t we go out for a change?
-> How ....about going out gor a change....?
5. This English book is old.
-> This ....is a old English book....
6. How much does this bar of soap cost?
-> What is ....the price of this bar....?
7. How long is the Red river?
-> What ....is the length of the Red river....?
8. My mother often goes to work at seven fifteen.
-> At a ....quarter past seven my mother often goes to work....
9. Ngan walks to school every morning.
-> Ngan goes ....to school on foot every morning....
10. How tall are you, Lan?
-> What ....is your height, Lan....?

So sánh hai số thì:

 64^27>16³²

  Đ/s:........................

các bạn giúp mình làm câu A với

72 qua day

tương,tường,tượng,tướng

đề sai vì cd > cr

dug de ace