câu hỏi ở dưới bài hơi nhiufa j 

câu hỏi ở dưới 

Cho tam giác nhọn ABC có H là trực tâm, các đường cao AD, BE và CF. Chứng minh rằng:

a) Tam giác AEF đồng dạng với tam giác ABC.

b) H là giao điểm các đường phân giác của tam giác DEF.

c) BH.BE+CH.CF=BC^2

VIDEO 1: Watch the song “Caravan Of Life” and fill in each blank with ONE suitable word.

What can you say
When you see it all just slip away
Wasting up(1) ____________

A chance went begging but you wouldn't play
All you had to do was ask
How (2) ____________   the time does pass
Everyday gets shorter
See how the years fly by

(3) ____________   that never were fulfilled
Tales no lips can ever tell
You get no second (4) ____________
This ticket's good one way

You can't change the days gone by
Doesn't matter how you try
Watch the hands of time march on
And see the (5) ____________   of life go by

And so one day soon
Perhaps we'll come to know the (6) ____________

 When our race is almost run
And we have paid the keeper's price with youth

Once again we all (7) ____________

How quickly the time does pass
Everyday gets shorter
See how the years fly by
Hopes we never (8) ____________

Times we never even try
You get no second chances
This ticket's good one way

You can't change the days gone by
Doesn't matter how you try
Watch the hands of time march one
And see the caravan of life go by.
 

VIDEO 2:Watch the clip “The rainforest” and circle the best answer (A, B or C)

1. One essential requirement for the existence of a rainforest is

A. a humid climate

B. a foggy climate

C. a warm climate

2. Which country is NOT mentioned as having the largest amount of rainforest in the world?

            A. Angola

            B. Ecuador

            C. Papua New Guinea

3. How much does it rain per year?

            A.8 inches                   B. 18 inches                            C. 80 inches

4. What percentage of the world's population of plants and animals lives in the rainforests?

A. just 50%                  B. less than 50%                     C. more than 50%

5. The Amazon Rainforest is

            A.the biggest on Earth

            B. the oldest on Earth

            C. the wettest on Earth

6. How many bridges are there over the Amazon river?

            A.none             B. very few                              C. a lot

Cho hàm số y = (1 - 2m)x - 2m + 5. Đồ thị hàm số cắt trục tung tại điểm có tung độ bằng -1 khi m =

Tìm các số tự nhiên x và y biết:

4/x = y/21 = 28/49

Cho các phân số: 12/21; 4/98; 36/63; 17/13; 33/77

a) Các phân số tối giản:

b) Các phân số chưa tối giản:

c) Rút gọn các phân số chưa tối giản:

Cho tam giác ABC vuông tại A với AC = 3cm, BC = 5cm. Vẽ đường cao AK.

a) Chứng minh rằng: tam giác ABC ~ tam giác KBA và AB^2 = BK.BC.

b) Tính độ dài AK, BK, CK.

c) Phân giác góc BAC cắt BC tại D. Tính độ dài BD.

2^16 +2^7 /2^3+2^12

$$\begin{gathered} 345,6:72= \\ 99,3472:32,68= \end{gathered}$$