\(\frac{a}{b}=\frac{c}{d}=\frac{a+c}{b+d}\)(Tính chất dãy tỉ số bằng nhau)

=> \(\frac{a^{1994}}{b^{1994}}=\frac{c^{1994}}{d^{1994}}=\frac{\left(a+c\right)^{1994}}{\left(b+d\right)^{1994}}=\frac{a^{1994}+c^{1994}}{b^{1994}+d^{1994}}\)(Tính chất dãy tỉ số bằng nhau)

=> \(\frac{\left(a+c\right)^{1994}}{\left(b+d\right)^{1994}}=\frac{a^{1994}+c^{1994}}{b^{1994}+d^{1994}}\)

=> Đpcm

Câu 2 tớ đăng phía dưới rồi đó.

Câu 3 đang định đăng lên thì cậu đăng là sao hả?

I

1, B

2, D

3, A

4, C

5, D

II

1, D

2, D

3, D

4, B

5, B

Các phép tính đó là :

(2.2)-(2.2)=0
2:2:2:2=1
(2-2):2+2=2
(2.2.2):2=3
(2:2).2.2=4

I, Viết lại câu sao cho nghĩa ko thay đổi

1. The Red river is 1,200 kilometers long. The Nile River is 6,437 kilometers long

=> The Nile River is much longer than the red river is.

2. Hung is 1.60 meters tall. Ba is 1.50 meters tall

=> Ba is 10 meters taller than Hung is.

3. How often do Ba and Lan go to the zoo a month

=> How many times do ba and Lan go to the zoo a month

Tìm và sửa 1 lỗi sai trong các câu sau :

1.They like watch T.V.>> watching

2.He comes here with bicycle.>> by

3.How many childs are there in the room ?>> children

1 Mai said "Let's swim hể tômrow

>Mai suggested swimming here tomorrow.

2 My teacher asked me " Do you finish your homework"

>My mothet asked me If I finished my homework.

3 I can hardly do thí asignment

>I wish I could hardly do this aignment.

4 My friend is a hard student. She always finishes her homework before going to class (Who)

>> My friend Who always finishes her homework before going to class is a hard student.

5 If/he/want/get/good marks/he/have/study/hard everyday

>> If he wants to get good mark, he will have to study hard everyday.

6 My friend /live/Le Loi street/be/good at/learn/English

>> My friend Who lives on Le Loi street is good at learning English.

7 My uncle /said/leave/here/Ha Noi/tomorrow

>> My uncle said that he would leave here to ha Noi the following day.

8 Despite working hard , he couldn't pass the final exam (Even though)

>> Even though he worked hard, he couldn't pass the final exam

9 Nam/arriveschool/on time/f/have/alarm/clock

>> Nam will arrive school on time If ha has an alarm clock.

10 Viet Nam /be/south-east asia/export/lot/rice/coffee

>> Viet nam is the south-east asia Where exports a lot of rice and coffee

11 Mai/wish/will/visit/parents/next week

>> mai wishes she would visit her parents next week

12 The boy is very poor His parent died ten years ago (Whose)

>> The boy Whose His parent died ten years ago is very poor

13 Nam said to me "I'm waiting for my parents now"

>> Nam said to me that he was writting for his parents then.

14 Despite the heavy snow , we went home on time

> Although it snowed heavily, we went home on time

15 " What do you usually do in your free time ?" He asked me

>He asked me What I usaully did in my free time.