Chứng minh rằng giá trị của biểu thức sau không phụ thuộc vào giá trị của biến: (x – 5)(2x + 3) – 2x(x – 3) + x + 7

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I. Chọn phương án đúng theo câu điều kiện loại I. (Choose the correct option according to conditional sentence type I.) 1. If we don’t protect the animals, they___________extinct, (becomes/will become) 2. If people___________down tree in the forest, there will be more floods. (cut/cuts) 3. If you___________recycle products, you’ll help to save the world, (will use/use) 4. You___________energy if you turn off the lamp, (save/will save) 5. They.................. the exam if they don’t study harder, (won’t pass/don’t pass) 6. If it........ tomorrow, I won’t have to water the plants, (rains/will rain) 7. What...... if they don’t stop destroying the forest? (will we do/do we do) 8. If we ........ everybody about deforestation, they will hear us. (tell/ will tell) 9. The city............ hot if we don’t grow tree, (is/will be) 10. Plastic garbage ...................out to the sea if we throw it into a river. (floats /will float) II. Viết dạng đúng của động từ ở câu điều kiện loại I. (Write the correct form of the verbs in conditional sentence type I.) 1. If you.........(not. study). you.......(fail) the test. 2. How......(we. live) if we..............(not. have) clean water? 3. If you.....................(look) at the city, you.........................(find) many buildings. 4. We..........plan) for a cleaner world if we..............(look) to the future. 5. There................(be) fewer storms if everybody.........(plant) a tree. 6. The sea level............(rise) if the planet.............(get) hotter. 7. If we............(reduce) air pollution, it.................(cut) rates of lung cancer. 8. The world..................(become) greener if people.....(use) bicycles instead of cars 9. If we.........(waste) time, we..........(lose) lots of things. 10. Hoa.....(feel) easy if she.......(breathe) fresh air. III. Viết ra từ cỏ âm /a:/ hoặc /æ/ khác với những từ còn lại. (Write down the word having /a:/ or /æ/ that is sounded different from the rest.) 1. cat, am, hat, chart 2. heart, arm, chat, hard 3. cart, had, map, band 4. garden, card, back, father 5. black, add, park, rat IV. Khoanh tròn từ có âm /a:/ và gạch chân từ có âm /æ/. (Circle the words having sound /a:/ and underline the words having sound /æ/.) 1. That cat is fat. 2. Happy and sad are far similar. 3. The man in black pants is my father. 4. Minh parked the car near the garden. 5. The hard part is to start the cart.