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tui gủi lại

bài 3: Nhà bạn Lan nuôi 5 con thỏ.Hỏi có bao nhiêu cái chân thỏ 

3,

Ta có

\(\tan\widehat{ABH}=\tan41,5^0=\dfrac{AH}{BH}\approx1\Leftrightarrow AH\approx BH\)

\(\tan\widehat{ACH}=\tan32^0=\dfrac{AH}{CH}\approx1\Leftrightarrow AH\approx CH\)

Vậy \(AH\approx\dfrac{BH+CH}{2}=\dfrac{BC}{2}=150\left(m\right)\)

4, Bài này mình làm tròn đến hàng đơn vị nhé

\(\tan\widehat{B}=\tan30^0=\dfrac{AH}{BH}=\dfrac{\sqrt{3}}{3}\Leftrightarrow AH=\dfrac{\sqrt{3}BH}{3}\)

\(\tan\widehat{ACH}=\tan35^0=\dfrac{AH}{CH}\approx1\Leftrightarrow AH\approx CH\)

\(\Leftrightarrow\dfrac{\sqrt{3}}{3}BH\approx CH\)

Mà \(BH-CH=BC=1500\Leftrightarrow BH-\dfrac{\sqrt{3}}{3}BH=1500\)

\(\Leftrightarrow\dfrac{3-\sqrt{3}}{3}BH=1500\\ \Leftrightarrow\left(3-\sqrt{3}\right)BH=4500\\ \Leftrightarrow BH=\dfrac{4500}{3-\sqrt{3}}=\dfrac{4500\left(3+\sqrt{3}\right)}{6}=750\left(3+\sqrt{3}\right)\left(cm\right)\)

\(\Leftrightarrow AH=\dfrac{\sqrt{3}}{3}BH=\dfrac{\sqrt{3}}{3}\cdot750\left(3+\sqrt{3}\right)=250\sqrt{3}\left(3+\sqrt{3}\right)\\ AH=750\sqrt{3}+750\left(cm\right)\)

Vậy ...

Đề đâu bạn?

-7-4=-11

-11

`-7-4=-(7+4)=-11`

let's start our tour in ho chi minh. we are in HAI BA TRUNG street now.first,go to straigh and take the second turning.it's on your left.finally,you are on saigon opera house.

2. should I do

3. you shouldn't eat

4. you should change

5. should I sleep

6. you shouldn't watch

7. you should go

8. You should do