ma sợ: thứ mà ma sợ đó! chứ còn j nữa <(^_^<)

2,7 g nhôm = 1cm³

=> 1 g nhôm có thể tích là \(\dfrac{1}{2,7}\) cm³

Tương tự , 1g sắt có thể tích là \(\dfrac{1}{7,8}\) cm³

mà 2 thanh có khối lượng bằng nhau => nhôm có thể tích lớn hơn ( vì \(\dfrac{1}{2,7}>\dfrac{1}{7,8}\))

Nhôm có thể tích lớn hơn số lần là \(\dfrac{1}{2,7}:\dfrac{1}{7,8}\)= \(\dfrac{1}{2,7}.7,8\) = \(\dfrac{7,8}{2,7}\)\(\approx\) 2,9 lần

3x²y² : x² = 3y²

1.She studies very well. She is a very ___industrial______ student.

2.Music makes a funeral more solemn and ___mourner______.

3. Everglades Nation Park is a sub-tropical __wild_______ in the United State.

4. Children can't be _____depend____ on their parents all the life.

5.For centuries, people have been curious about ____mystery_____ lying beneath the ocean.

6.John Aspinall is famous for his program of saving __dangerous_______animals.

7.Man is causing ____pollution_____(pollute) that can harm marine-life.

8. People must learn about how to keep the environment _______unpolluted__.

9.He won the discuss event at the Olympic Games but was later _____qualified____ when a medical check proved that he had been taking drugs.

10.Do you have a ____national_____ costume of your country?

11.The plane had to make a crash ____land_____ in a field.

12. Travelling in big cities is becoming more ______troubled___ everyday.

1. He completely agreed with what I said.

2. Helen was the last applicant to be interviewed

3. I can’t find my purse anywhere; I must leave it at the cinema

4. Hoi An is famous for its old streets.

5. The sheet of paper slipped off his hand falling down the ground.

6. Remember not to tell anyone about my mistake.

7. The girl is standing in the room looking at herself in the mirror.

8. My little son is not old enough to get his own bed

9. The meal will be served for about ten minutes.

10. Have you made up your mind to buy a new house yet?

11. Why don’t we take Lisa along with us on our next trip?

12. When I was younger, I never used to smoke or drink.

13. When I questioned him, he finally admitted stealing my pen.

14.Would you mind if I used your mobile phone?

15. Don’t worry. We will inform of the test results next week.

Câu 2 :

\(\dfrac{x^3+2x^2y+xy^2}{x^2-y^2}\)= \(\dfrac{x\left(x^2+2xy+y^2\right)}{\left(x-y\right)\left(x+y\right)}\)= \(\dfrac{x\left(x+y\right)^2}{\left(x-y\right)\left(x+y\right)}\)

Rồi bn triệt tiêu x+y ở tử với mẫu đi sẽ dc kết quả là \(\dfrac{x\left(x+y\right)}{x-y}\)

Circle the word whose underlined, bold part is pronounced differently from the rest

A. brown

B. cow

C. bowl

D. owl

Ta có:3²⁰=(3²)¹⁰=9¹⁰

         2³⁰=(2³)¹⁰=8¹⁰

Vì 9¹⁰>8¹⁰ nên 3²⁰>2³⁰

351

12 = 2². 3                                15 = 3 .5                                                                18 = 2. 3²                                                                                                        BCNN ( 12 ; 15 ; 18 ) = 2² . 3² . 5 = 180                                                                                                                                                      BC ( 12 ; 15 ; 18 ) = B (180) = { 0 ; 180 ; 360 ; 540 ; ... }                                                                                                                             Vì 150 < a <400 nên a thuộc { 180 ; 540 }                                         Vậy có 2 phần tử !!!              tick mk nha !!!