chứng Minh rằng biểu thức: A=x(x-6)+10 luôn luôn dương với mọi x B=x^2-2x+9y^2-6y+3 luôn luôn dương với mọi x,y

Các câu hỏi liên quan

• BÀI TẬP TỔNG HỢP NÂNG CAO • Chọn đáp án thích hợp điền vào chỗ trống • You ________________ go to the hairdresser’s. A. should B. will C. shall • It’s incredible that Stuart ________________ run so fast. A. should B. will C. shall • ________________ you have some coffee? She asked us. A. should B. will C. shall • You ________________ read this book, it is worth reading A. should B. will C. shall • She ________________ probably come tomorrow. A. should B. will C. shall • Let’s go for a walk, ________________ we? A. should B. will C. shall • ________________ you tell me where you are from? No I won’t. A. should B. will C. shall • ________________ we go somewhere else? A. should B. will C. shall • Chọn should/ must/ mustn’t/ have to/ don’t have to để điền vào chỗ trống. • I don’t think you ________________ eat so much chocolate. It’s bad for your health. • Children ________________ behave well when they’re in class. • If you drive a car, you ________________ stop at marked crossings. • I think waiters ________________ try to be pleasant with customers. • Some workers ________________ wear hard hats because their jobs are considered dangerous. • If you feel sick, you ________________ stay at home. It’s better for you. • Police officers ________________ wear a uniform. • I ________________ do my homework. My teacher always checks if we have done the exercises. • I ________________ get my hair cut. I don’t like long hair. • We ________________ go home. My mother has told me to arrive at ten o’clock. • I ________________ study hard. I want to pass the exam. • In Spain, children ________________ go to school until they’re 16. • You ________________ phone every day, darling! • You ________________ accept things from strangers! • When you go into a clothes shop, you ________________ have to buy something. You can just look • You ________________ steak things from shops. • Children ________________ pay bills. • Children ________________ eat junk food every day.

giúp mình bài này nha cần gấp :2. All the roads were flooded because it had been raining heavily. (due to) ____________________________________________________________________ 3. Jimmy yate a lot of fast foods, so he put on 10 kilograms within just two months. (because) ____________________________________________________________________ 4. My father got upset because I repeatedly left on the lights I was not using. (so) ____________________________________________________________________ 5. The contaminated drinking water caused the outbreak of cholera in the village (due to) ____________________________________________________________________ 6. Human activity is to blame for many forms of pollution on earth. (resulted in) ____________________________________________________________________ II. Complete the second sentence so that it has a similar meaning to the first sentence. 1. The soil is poisoned because farmers use too many pesticides and herbicides. If__________________________________________________    2. I can’t help you unless you tell me what’s wrong.  If__________________________________________________    3. Many people have stomachache due to the contaminated food. If__________________________________________________    4. Stop swimming in that lake, or you will have skin rashes. If__________________________________________________    5. John lives in the area affected by air pollution, so he has breathing problem. If__________________________________________________    III. Use the suggestions below to write a short paragraph of 80-120 words about Land Pollution.