Topic 3: Write a paragraph (50 – 70 words) about your daily habits that help you stay healthy. To stay healthy, I always try to eat well and do exercise every day. I eat a lot of vegetables, fruits, and fish because they are good for my body. I don’t eat much fast food or drink soft drinks. Every morning, I go jogging in the park for about thirty minutes. It helps me feel fresh and full of energy. I also sleep at least eight hours a night and drink enough water. These simple habits make me strong, healthy, and ready for a new day.

1 Emma usually goes jogging in the park in the mornings 2My brother likes playing football on Sunday afternoon.

1. It's not good idea to stay up too late before an exam.

→ You _shouldn't stay up too late before an exam_________________________________________________________.

2. The shopping mall is in front of my favorite coffee shop.

→ My favorite coffee shop My favorite coffee shop is behind the shopping mall________________________________________.

3. I'd rather watch TV than read books.

→ I prefer prefer watching TV to reading books._______________________________________________________.

a) \(24 , 3. \left(\right. \frac{- 11}{25} \left.\right) + \left(\right. \frac{- 11}{25} \left.\right) . 75 , 7\)

\(= \left(\right. 24 , 3 + 75 , 7 \left.\right) . \left(\right. \frac{- 11}{25} \left.\right)\)

\(= 100. \left(\right. \frac{- 11}{25} \left.\right) = - 44\)

b) \(\left[\right. \left(\right. 9^{2} : 3^{2} \left.\right) + \left(\right. 125 : 5^{2} \left.\right) \left]\right. . \left(\right. \frac{- 1}{2} \left.\right)^{2}\)

\(= \left[\right. \left(\right. 3^{4} : 3^{2} \left.\right) + \left(\right. 5^{3} : 5^{2} \left.\right) \left]\right. . \frac{1}{4}\)

\(= \left(\right. 3^{2} + 5 \left.\right) . \frac{1}{4}\)

\(= 14. \frac{1}{4} = \frac{14}{4} = \frac{7}{2}\)

c) \(\sqrt{16} + \sqrt{100} - \sqrt{36}\)

\(= 4 + 10 - 6 = 14 - 6 = 8\)\(\)

a) \(24 , 3. \left(\right. \frac{- 11}{25} \left.\right) + \left(\right. \frac{- 11}{25} \left.\right) . 75 , 7\)

\(= \left(\right. 24 , 3 + 75 , 7 \left.\right) . \left(\right. \frac{- 11}{25} \left.\right)\)

\(= 100. \left(\right. \frac{- 11}{25} \left.\right) = - 44\)

b) \(\left[\right. \left(\right. 9^{2} : 3^{2} \left.\right) + \left(\right. 125 : 5^{2} \left.\right) \left]\right. . \left(\right. \frac{- 1}{2} \left.\right)^{2}\)

\(= \left[\right. \left(\right. 3^{4} : 3^{2} \left.\right) + \left(\right. 5^{3} : 5^{2} \left.\right) \left]\right. . \frac{1}{4}\)

\(= \left(\right. 3^{2} + 5 \left.\right) . \frac{1}{4}\)

\(= 14. \frac{1}{4} = \frac{14}{4} = \frac{7}{2}\)

c) \(\sqrt{16} + \sqrt{100} - \sqrt{36}\)

\(= 4 + 10 - 6 = 14 - 6 = 8\)\(\)

Vì \(M N / / B C\) nên \(\hat{A C B} = \hat{A N M} = 4 0^{\circ}\) và \(\hat{A B C} = \hat{A M N} = 5 0^{\circ}\)

Vì \(C D\) là phân giác góc \(A C B\) nên \(\hat{D C B} = 4 0^{\circ} : 2 = 2 0^{\circ}\)

Vì \(B D\) là phân giác góc \(A B C\) nên \(\hat{D B C} = 5 0^{\circ} : 2 = 2 5^{\circ}\)

Vậy \(\hat{D C B} < \hat{D B C}\)

Vì \(M N / / B C\) nên \(\hat{A C B} = \hat{A N M} = 4 0^{\circ}\) và \(\hat{A B C} = \hat{A M N} = 5 0^{\circ}\)

Vì \(C D\) là phân giác góc \(A C B\) nên \(\hat{D C B} = 4 0^{\circ} : 2 = 2 0^{\circ}\)

Vì \(B D\) là phân giác góc \(A B C\) nên \(\hat{D B C} = 5 0^{\circ} : 2 = 2 5^{\circ}\)

Vậy \(\hat{D C B} < \hat{D B C}\)

Vì \(M N / / B C\) nên \(\hat{A C B} = \hat{A N M} = 4 0^{\circ}\) và \(\hat{A B C} = \hat{A M N} = 5 0^{\circ}\)

Vì \(C D\) là phân giác góc \(A C B\) nên \(\hat{D C B} = 4 0^{\circ} : 2 = 2 0^{\circ}\)

Vì \(B D\) là phân giác góc \(A B C\) nên \(\hat{D B C} = 5 0^{\circ} : 2 = 2 5^{\circ}\)

Vậy \(\hat{D C B} < \hat{D B C}\)

Vì \(M N / / B C\) nên \(\hat{A C B} = \hat{A N M} = 4 0^{\circ}\) và \(\hat{A B C} = \hat{A M N} = 5 0^{\circ}\)

Vì \(C D\) là phân giác góc \(A C B\) nên \(\hat{D C B} = 4 0^{\circ} : 2 = 2 0^{\circ}\)

Vì \(B D\) là phân giác góc \(A B C\) nên \(\hat{D B C} = 5 0^{\circ} : 2 = 2 5^{\circ}\)

Vậy \(\hat{D C B} < \hat{D B C}\)

Gọi số học sinh lớp \(7 B\) là \(x\) \(\left(\right. x \in \mathbb{N}^{*} \left.\right)\) (học sinh)

Số học sinh ban đầu lớp \(7 A\) là \(\frac{4}{5} x\) (học sinh)

Theo đề bài, ta có: 

 \(\frac{4}{5} x - 8 = \frac{1}{2} \left(\right. x + 8 \left.\right)\)

 \(\frac{4}{5} x - 8 = \frac{1}{2} x + 4\)

\(\frac{3}{10} x = 12\)

\(x = 40\) (thỏa mãn)

Vậy số học sinh là \(7 B\) là \(40\) học sinh

Số học sinh lớp \(7 A\) là: \(40. \frac{4}{5} = 32\) (học sinh)

Tổng số học sinh lớp \(7 A\) và lớp \(7 B\) của một trường là: \(40 + 32 = 72\) (học sinh)