A. Correct order of sentences:

1.While I was surfing the Internet, I came across an article on how to learn English effectively.

2.Before you start learning English right now, it is important that you find out your level of English.

3.If you can't find English books or the news on the Internet, use them to read every day.

B. Rewrite the sentences:

1.I searched the lyrics as I wanted to learn the English vocabulary used in the song.

2.Students should find a language exchange group to practice speaking with other learners.

Exercise regularly brings many benefits, especially for young people. It helps your body grow stronger and more flexible, improving overall health. Regular activity can also boost energy levels, improve focus, and help you sleep better. Doing sports or workouts helps reduce stress and makes you feel happier because it releases endorphins, the "feel-good" hormones. Exercise also reduces the risk of health problems, such as heart disease and diabetes, by keeping your body healthy and active. In short, regular exercise helps you stay fit, happy, and strong.

Exercise regularly brings many benefits, especially for young people. It helps your body grow stronger and more flexible, improving overall health. Regular activity can also boost energy levels, improve focus, and help you sleep better. Doing sports or workouts helps reduce stress and makes you feel happier because it releases endorphins, the "feel-good" hormones. Exercise also reduces the risk of health problems, such as heart disease and diabetes, by keeping your body healthy and active. In short, regular exercise helps you stay fit, happy, and strong.

(7x ‒1)2 = 4(1 ‒ 2x)2

(7x ‒ 1)2 ‒ 4(1 ‒ 2x)2 = 0

(7x ‒ 1)2 ‒ [2.(1 ‒ 2x)]2 = 0

(7x ‒ 1)2 ‒ (2 ‒ 4x)2 = 0

[(7x ‒ 1) ‒ (2 ‒ 4x)].[(7x ‒1) + (2 ‒ 4x)] = 0

[7x – 1 – 2 + 4x].[7x – 1 + 2 – 4x] = 0

(11x ‒ 3)(3x + 1) = 0

11x ‒ 3 = 0 hoặc 3x + 1 = 0

11x = 3 hoặc 3x = –1

 hoặc .

  Vậy ta có hai nghiệm là  và 

Giải thích các bước giải:

 y = x - 4009

=> x - y = 4009

 x-1/2005 = 3-y/2006 = x-1+3-y/2005+2006

     = 4011/4011 = 1

=> x = 2006

     y = -2003

Giải thích các bước giải:

 y = x - 4009

=> x - y = 4009

 x-1/2005 = 3-y/2006 = x-1+3-y/2005+2006

     = 4011/4011 = 1

=> x = 2006

     y = -2003

Giải thích các bước giải:

 y = x - 4009

=> x - y = 4009

 x-1/2005 = 3-y/2006 = x-1+3-y/2005+2006

     = 4011/4011 = 1

=> x = 2006

     y = -2003.

a.565-13x=370

  13x=565-370

  13x=195

      x=195:13

       x=15

b. (-8)x=(-7).(-6)-2

    (-8)x=-42-2

    (-8)x=40

          x=40:(-8)

          x=-5

10.d

12.b

13.c