2 tá \(=24\)

Muốn mua 8 cái bút chì cần trả \(30000:24\times8=10000\left(VNĐ\right)\)

Số tiền phải trả khi mua 8 cái bút là:

\(30000:24\cdot8=10000\left(đồng\right)\)

1 tá=12:)
2 tá=24
Mua 1 cái thì phải trả:
       30 000 : 24 = 1 250(đồng)
Mua 8 cái thì phải trả:
       1 250 . 8 = 10 000(đồng)

Đ/s : 10 000 đồng:)

11. My sister walks to school.
12. The bank is near the post office.
13. Our garden has many flowers.
14. Ba doesn't live outside the city.
15. Nma doesn't live in the countryside.

11 My sister walks to school

12 The bank is near the post office

13 Our garden has many flowers

14 Ba doesn't live in the countryside

15 Nam doesn't live in the countryside

a=5k+1

Cho \(0\le5k+1\le100\)

=> \(0\le k\le19\)

Có 20 giá trị của k => A có 20 phần tử

a=5k+1

Cho 0≤5k+1≤1000≤5k+1≤100

=> 0≤k≤190≤k≤19

Có 20 giá trị của k => A có 20 phần tử

Do AC, BD, KE là 3 đường cao nên chúng luôn đồng quy tại 1 điểm nên AC,BD,KE cùng đi qua 1 điểm

1. Have you met

2. did

3. are you going

4. Do you watch

5. have you lived

6. Did you have

7. did she wear

8. do 

9. What have you done

10. Have you gone

\(=\left(\dfrac{\sqrt{x}\left(\sqrt{x}+3\right)}{\left(\sqrt{x}+3\right)\left(\sqrt{x}-3\right)}-\dfrac{4}{\sqrt{x}\left(\sqrt{x}-3\right)}\right).\left(\dfrac{\sqrt{x}+2+\sqrt{x}-2}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+2\right)}\right)\)

\(=\dfrac{x-4}{\sqrt{x}\left(\sqrt{x}+3\right)}.\left(\dfrac{2\sqrt{x}}{x-4}\right)=\dfrac{2}{\sqrt{x}+3}\)

\(B=\dfrac{\sqrt{x-3-2\sqrt{x-3}+1}}{\sqrt{x-3}-1}=\dfrac{\sqrt{\left(\sqrt{x-3}-1\right)^2}}{\sqrt{x-3}-1}=\dfrac{\sqrt{x-3}-1}{\sqrt{x-3}-1}=1\)