3x + 22 = 46

3x = 46 - 22

3x = 24

x = 24 : 3

x = 8

Vậy x = 8

- Gọi số đầu tiên trong dãy các số tự nhiên liên tiếp là: x

Ta có:

x + (x + 1) + (x + 2) = 1194

x . 3 + (1 + 2) = 1194

x . 3 + 3 = 1194

x . 3 = 1194 - 3

x . 3 = 1191

x = 1191 : 3

x = 397

=> Số lớn nhất trong dãy ba số tự nhiên liên tiếp là: (x + 2)

=> Số đó là: 397 + 2 = 399

Vậy số đó là 399

S = 1 - 2 + 3 - 4 + 5 - ... + 199 - 200 + 201

S = (1 - 2) + (3 - 4) + 5 - ... + (199 - 200) + 201

S = (- 1) + (- 1) + (- 1) ... + (- 1) + 201

Ta có:

Từ 1 đến 200 có 200 số số hạng

=> Số - 1 trong các nhóm là: 200 : 2 = 100 (số)

S = - 100 + 201

S = 201 - 100

S = 101

3^{2x - 14} = 81

3^{2x - 14} = 3⁴

=> 2x - 14 = 4

=> 2x = 14 + 4

=> 2x = 18

=> x = 18 : 2

=> x = 9

676 . 17 + 17 . 160 + 164 . 17

= (676 + 160 + 164) . 17

= 1000 . 17

= 17 000

Đề bài: 2x³ + 3x² + 4x + 5 với x = 3

Ta có:

2x³ + 3x² + 4x + 5

= 2 . 3³ + 3 . 3² + 4 . 3 + 5

= 2. 27 + 3 . 9 + 12 + 5

= 54 + 27 + 12 + 5

= 81 + 12 + 5

= 93 + 5

= 98

Vậy p = 98

Dear diary,

Today, I meet my best friend. Her name is Tu Vy. She has long hair and a round face. She is very active and kind. She always helps me when I need. I like her because she has a attractive smile with her great sense of humor.

Thi

Dear Mai,

My neighbourhood is in Hanoi. In Hanoi, I can see a lot of shops, museums and theater. It's really crowded and busy. Everyday, there are lots of traffics that cause traffic jams. The air is so polluted, not like in my countryside so I don't want to live in Hanoi very much. How about you? What's your neighbourhood like?

Thi

Tran Phuc Giang Thi

1. Because I didn't have any class yesterday, so I played sports.

2. Althought she is short, she still plays basketball.

3. How about playing badminton this weekend?

4. The life in the city isn't as exciting as the life in the country.

5. What a wonderful trip!

6. The huge villa is theirs.

1. She walks to school every morning.

2. They are learning how to use the lawn mower in the garden.

3. Linda goes to the supermarket to buy some sugar.

4. Sometimes I feel really lazy to do anything.

5.  Phong and I are studying English in my room.

6. I often have breakfast at 7 a.m at home.

7. She does aerobics every morning to keep fit.

8. Nga likes playing basketball very much.

9. What time do you have lunch every day?

10: She doesn't have any pen, so I lend her one.