Bài 2

5 C

Bài 3

1 D

6 C

Còn lại ol r nhé

2) 5. C

3) 2. D

6. C

Còn lại ok nha

3/5:x=1/3

x=3/5:1/3

x=9/5

\(\frac{3}{5}\div x=\frac{1}{3}\)

\(x=\frac{3}{5}\div\frac{1}{3}=\frac{9}{5}\)

3/5:x=1/3

       x=3/5:1/3

       x=3/5×3/1

         x=9/5

vậy x=9/5

6)  \(\dfrac{8^6}{256}=\dfrac{\left(2^3\right)^6}{2^8}=\dfrac{2^{18}}{2^8}=2^{10}=1024\)

7) \(\left(\dfrac{1}{2}\right)^{15}.\left(\dfrac{1}{4}\right)^{20}=\left(\dfrac{1}{2}\right)^{15}.\left[\left(\dfrac{1}{2}\right)^2\right]^{20}=\left(\dfrac{1}{2}\right)^{15}.\left(\dfrac{1}{2}\right)^{40}=\left(\dfrac{1}{2}\right)^{55}=\dfrac{1}{2^{55}}\)

8)  \(\left(\dfrac{1}{9}\right)^{25}\div\left(\dfrac{1}{3}\right)^{30}=\left(\dfrac{1}{3}\right)^{50}\div\left(\dfrac{1}{3}\right)^{30}=\left(\dfrac{1}{3}\right)^{20}=\dfrac{1}{3^{20}}\)

9)\(\left(\dfrac{1}{16}\right)^3\div\left(\dfrac{1}{8}\right)^2=\left(\dfrac{1}{2}\right)^{12}\div\left(\dfrac{1}{2}\right)^6=\left(\dfrac{1}{2}\right)^6=\dfrac{1}{64}\)

10)  \(\dfrac{27^2.8^5}{6^2.32^3}=\dfrac{3^6.2^{15}}{3^2.2^2.2^{15}}=\dfrac{3^4}{2^2}=\dfrac{81}{4}\)

Câu 1: D

Câu 2: C

Câu 3: C

Câu 4: D

Câu 5: A

 1: D

 2: C

 3: C

 4: D

 5: A

Học sinh phải:

- Tuân theo Hiến pháp, pháp luật.

- Tham gia bảo vệ Tổ quốc, trật tự an toàn xã hội.

- Bảo vệ bí mật quốc gia.

- Chấp hành các quy định nơi công cộng.

Bài 2: 

Ta có: \(3n^3+10n^2-5⋮3n+1\)

\(\Leftrightarrow3n^3+n^2+9n^2+3n-3n-1-4⋮3n+1\)

\(\Leftrightarrow3n+1\in\left\{1;-1;2;-2;4;-4\right\}\)

\(\Leftrightarrow3n\in\left\{0;-3;3\right\}\)

hay \(n\in\left\{0;-1;1\right\}\)

#Tham khảo!!

All of the special holidays in my country, I like Tet the most. Tet is an occasion to everyone get together in warm atmosphere. Before Tet holiday, Everyone prepares many things and decorates their house. I plant a lot of flowers in front of my house and buy many things such as clothes, foods. Besides, most of the streets also are decorated beautifully with colorful lights and flowers. During Tet, I spends more time on visiting my relatives, friends and colleagues. Especially, I give to each other the best wishes for the new year. Tet is an opportunity for children receive lucky money. There is a funny thing that people try to avoid argument or saying any bad things at Tet. I love Tet holiday

Tet is an important holiday in Viet Nam. At Tet, everyone who works in everywhere comes back to their family. There are many activities at Tet. And the things which make children excited is lucky money. I love Tet so much