Đáp án+Giải thích các bước giải:
Gọi $Δ$ đó là $ΔABC$ đường cao $AH$ ta có:$HB+HC=BC=3+4=7$$AB^2=HB.BC$ (Hệ thức lượng)$⇒AB=\sqrt{HB.BC}=\sqrt{3.7}=\sqrt{21}$$AC^2=HC.BC$$⇒AC=\sqrt{HC.BC}=\sqrt{4.7}=2\sqrt{7}$
Gọi các cạnh góc vuông của tam giác đó lần lượt là x ; y (x , y > 0)
Áp dụng hệ thức 1 về cạnh và đường cao trong tam giác vuông ta có :
x² = 3.7
⇒ x = $\sqrt{21}$ (tmđk)
y² = 4.7
⇒ y = 2$\sqrt{7}$ (tmđk)
Vậy các cạnh góc vuông của tam giác vuông đó là $\sqrt{21}$ ; 2$\sqrt{7}$
Choose the correct answer to complete the sentences below. 1. Surgeons use a ______________ to perform an operation. A. scalpel B. razor blade C. sword D. knife 2. He is always busy. He has ______________ time to relax. A. much B. a little C. little D. few 3. She’s running slowly through the park. She’s ______________. A. walking B. riding C. jogging D. driving 4. How do you say this fraction 3/5 in English? A. three over fifth B. three-fifth C. three-fifths D. three-fives 5. Peter’s parents are very ______________ with his success. A. please B. pleasant C. pleasing D. pleased 6. He is interested in ______________ research. A. working B. making C. studying D. doing 7. Every student ______________ to finish this test in 45 minutes. Are you all ready? A. having B. has C. had D. have 8. He couldn’t go on a long holiday as he had ______________ days off. A. a lot of B. a little C. a few D. few 9. My sister is a ______________ student. She’s never late ______________ class. A. serious/for B. hard/in C. busy/ for D. studious/with 10. They work ______________ at the hotel. A. full-time B. part-timed C. full-timed D. whole-time
Giúp em câu này nha m.n e đg gấp! Cảm ơn nhiều! Ai lm xong e cho 5 sao nhé
V. Rewrite the second sentence so that it has a similar meaning to the first one. (1.0 mark) 1. The Central Tower is the tallest building in this city. → No building in this city_______________________________________________________________ . 2. It was raining hard. They could not work in the fields. → It was raining so____________________________________________________________________ . 3. People say that he is a great teacher. → It is______________________________________________________________________________ . 4. He said "Let's go out for dinner!" → He suggested______________________________________________________________________ .
IV. Give the correct form of the words given to complete each of the following sentences. Write your answers in the gaps provided. (1.0 mark) 1. We take part in a lot of activities in our community. (culture) 2. The photo brought back many happy memeories of my . (child) 3. We used to of our home village when we lived overseas. (thought) 4. , we used to cook five-colour sticky rice on the first day of the lunar month. (tradition)
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Làm hộ mình bài 6.Tổng số cây ba lớp là 132 nha
Cần gấp ạ mong mn giúp đỡ ạ 5 sao
Em cần rất gấp làm ơn giúp em. Sẽ vote 5 sao cho ai trả lời nhanh nhất.
Giúp em câu này nha m.n e đg gấp! Cảm ơn nhiều
`\sqrt{2x-3}/\sqrt{x-1}=2` giải pt
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