a/5=b/3=c/2 và a ²-b ²-c ²=48

2 câu trả lời

Đáp án:

a5 = b3 = c2 =a mũ 2 - b mũ 2 - c mũ 2 trên 5*5-3*3-2*2=

4812 =4

a5 =4 ⇒a=5*4=20

b3 =4 ⇒b=3*4=12

c2 =4 ⇒c=2*4=8

vậy a=20

b=12

c=8

chúc bạn học tốt

Đáp án:

Giải thích các bước giải:

Câu hỏi trong lớp Xem thêm

XI. Hoàn tất các câu sau với trạng từ thích hợp: 1. David Beckham is a good soccer player. He plays soccer very ............ 2. My father is a safe driver. He drives ............ 3. She is a skillful tennis player. She plays ............ 4. My mother is a slow cyclist. She cycles very ............ 5. I am a bad swimmer. I swim ............ 6. These children are quick runners. They run ............ XII. Chọn đáp án thích hợp nhất: 1. I always feel ............... before examinations. (nervous/ nervously) 2. He speaks English ............... (fluent/ fluently) 3. It is an ............ book. (interesting/ interestingly) 4. He drove ............... and he had an accident (careless/ carelessly) 5. We didn’t go out because it was raining ............... (heavy/ heavily) 6. The football match was very .................. I enjoyed it. (exciting/ excitingly) 7. She tried on the dress and it fitted her ............... (good/ well) 8. He never has accidents because he always drives ............... (careful/ carefully) 9. He behaved .................. towards his children. (strict/ strictly) 10. It’s too dark to see .................. (clear/ clearly) XIII. Viết câu sử dụng “ought to” or “ought not to”. 1. Her room is very dirty. (clean it every day) 2. I play tennis badly. (practice tennis more regularly) 3. My father has a sore throat. (not smoke so much) 4. Nam feels very tired. (go to bed early) 5. He had an accident last week. (not drive so fast) 6. I catch flu. (stay in bed) 7. Hoa feels sleepy. (not stay up late) 8. His shirt is very old. (buy a new one) XIV. Điền từ vào chỗ trống “can, must, should, ought” 1. You ............... wash your hand before meals. 2. John is very good at math. He ............ do all math problems. 3. It’s too late. I ............ go now. 4. She gets bad marks at chemistry. She ............ to study harder. 5. The traffic lights are red. You ............... stop. 6. ............... I go to the movies now? 7. Children ............... drink lots of milk. 8. He ............... to drive more carefully.

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