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1 Ann facies doing DIY in her free time.
2 My father prefers not eating out.
3 Mr. Smith loves going shopping at weekend.
1 Ann fancies doing DIY in her free time
2 My father prefers not eating out
3 Mr Smith loves going shopping at weekend
∆ABC có BE là đường phân giác (gt)
∆ABC vuông tại A (gt)
⇒ BC² = AB² + AC² (Pythagore)
⇒ BC² - AB² = AC²
= (3 + 5)²
= 64
Áp dụng tính chất của dãy tỉ số bằng nhau, ta có:
Ta có:
BC² = AB² + AC² (Pythagore)
= 6² + 64
= 100
⇒ BC = 10
vì BE là đường phân giác của tam giác ABC nên ta có:
\(\dfrac{AE}{EC}=\dfrac{AB}{BC}=\dfrac{3}{5}\)
\(BC=\dfrac{5}{3}AB\)
áp dụng định lý pythagore vào tam giác ABC ta được:
\(AC^2=AB^2+BC^2\)
tổng độ dài đoạn AC là: 3 + 5 = 8
\(AB^2+BC^2=8^2\\ AB^2+\left(\dfrac{5}{3}AB\right)^2=64\\ AB^2+\dfrac{25}{9}AB^2=64\\ AB^2\cdot\left(1+\dfrac{25}{9}\right)=64\\ AB^2\cdot\dfrac{34}{9}=64\\ AB^2=64:\dfrac{34}{9}=64\cdot\dfrac{9}{34}\\ AB^2=\dfrac{576}{34}\\ AB=\sqrt{\dfrac{576}{34}}\text{≈}4,11\)
độ dài đoạn BC là:
BC² = AC² - AB²
BC² = 64 - 16,8921
BC² = 47,1079
BC = \(\sqrt{47,1079}\) ≈ 6,86
VẬY AB = 4,11; BC =6,86
Đa thức $2x^4-21x^2+1$ không phân tích thành nhân tử bạn nhé.
1 to know
2 to meet
3 will tell
4 has just gone
5 has already known
6 to do
7 read
8 has just left
9 learn
#\(yGLinh\)
1. They ought ( know ) ..to know.. all the regulations in this school
2. It's very happy ( meet ) ..to meet. them again
3.I am sure they ( tell ) ..will tell. us about themselves soon
4. Nam isn't here. He ( just go ) .has just gone.. out for a walk
5. He (already know ) ..has already known. this regulation
6. Of us is ready ( do ) ..to do. the work
7. Have you ever ( read ) ...read. the story
8. Our teacher ( just leave ) ..has just left. the school
9. Pupils must ( learn) ..learn. their lessons before coming to class
Dưới đây là các câu hoàn chỉnh với các từ đã cho:
All of them have ready to give a book report. -> All of them are ready to give a book report.
We are much interested in English. -> We are very much interested in English.
Ask when he made the cake. -> Ask him when he made the cake.
Jane has never seen an elephant before. -> Jane has never seen an elephant before.
Enjoy books in spare time. -> I enjoy reading books in my spare time.
/s/: stops, arts, laughs, rocks
/iz/: quizzes, fixes, watches
/z/: friends, prefers
1. To learn the regulations is difficult
=> it is...difficult to learn the regulations.
2. To pratise swimming is good for your health
=> it is good for your health to practice swimming.
3. To help him write his name on the board was necessary
=> it was...necessary to help him write his name on the board.
4. To get acquainted with newcomers is easy
=> it is not... difficult to get acquainted with newcomers.
1. To learn the regulations is difficult
=> it is...difficult to learn the regulations
2. To pratise swimming is good for your health
=> it is good for your health to practise swimming
3. To help him write his name on the board was necessary
=> it was...necessary to help him write his name on the board
4. To get acquainted with newcomers is easy
=> it is not... difficult to get acquainted with newcomers
c++
1. you must never come into this room without knocking first
2. I need to buy a small gift for my friend
3. The little boy was very interested in reading picture books
4. She intends to make a book report
5. He seems be very tired after work
6. It is impossible to meet Peter at this time
7. You needn't shout loudly
1. you must never come into this room without knocking first
2. I need to buy a small gift for my friend
3. The little boy was very interested in reading picture books
4. She intends to make a book report
5. He seems to be very tired after work
6. It is impossible to meet Peter at this time
7. You needn't shout loudly