Giải thích các bước giải và đáp án:
1)
a. giải pt có nghiệm x=2 và x=1--> tập A={1;2}
b. giải pt có nghiệm x=-1 và x=1/2 mà các nghiệm thuộc Z-->tập B={-1}
c.giải pt có nghiệm x=2; x=√2; x=-2; x=-√2 vì các nghiệm thuộc N -->tập C={2}
2) (câu 2 chỉ có mỗi câu a thôi hả em)
a.A = {x ∈R |1< x <4 }
`~rai~`
\(1.x^2-3x+2=0\quad(a+b+c=0)\\\Leftrightarrow \left[\begin{array}{I}x=1\\x=2\end{array}\right.\\\Rightarrow x\in \{1;2\}\\\Rightarrow A=\{1;2\}.\\2.2x^2+x-1=0\quad(a-b+c)=0\\\Leftrightarrow \left[\begin{array}{I}x=-1\quad\text{(thỏa mãn)}\\x=\dfrac{1}{2}\quad\text{(không thỏa mãn)}\end{array}\right.\\\Rightarrow B=\{-1\}.\\c)x^4-6x^2+8=0\\\Leftrightarrow (x^2-4)(x^2-2)=0\\\Leftrightarrow \left[\begin{array}{I}x^2=4\\x^2=2\end{array}\right.\\\Leftrightarrow \left[\begin{array}{I}x=\pm 2\\x=\pm\sqrt{2}\end{array}\right.\\\text{mà }x\in\mathbb{Z}\Rightarrow x=2\\\Rightarrow C=\{2\}.\\2.\\a)D=\{x|x\in\mathbb{R};1<x<4\}.\)
So sánh : A với 1 A = 1/1.2 + 1/2.3 = 1/3/4 +...+1/49.50 gấp
Task 4. Combine these pairs of sentences using "too ....to" 1. The bag was very heavy. She couldn't carry it. ........ 2. He is very old. He can't run. ........ 3. She is very young. She can't go to school. ........ 4. Tom is very short. He can't play volleyball. ........ 5. It's very late. We can't go to the movies. ........ 6. The question was very hard. We couldn't answer it. ........ 7. The TV program is very exciting. The children won't miss it. ........ 8. You're very young. You can't drive that car. ........ 9. She was tired. She didn't go anywhere. ........ 10. These shoes are very small. I can't wear them. ........
Đang cần gấp ai giúp mình với ạ
Task 3. Combine these pairs of sentences using "so……..that" 1. That woman was very tall. She could almost touch the ceiling. ........ 2. This coat is very big. I can't wear it. ........ 3. The coffee was so strong. She couldn't go to sleep. ........ 4. That bag was very heavy. None of us could carry it. ........ 5. The stadium is very large. It can hold 60,000 people. ........ 6. Those lessons are very difficult. He can't understand them. ........ 7. She was very busy. She couldn't do the housework. ........ 8. The climate was very bad. All the plants couldn't grow well. ........ 9. I'm very tired. I couldn't keep my eyes open. ........ 10. That boy is very lazy. He never does his homework. ........
MN lm nhanh giúp em 2 bài này với ạ
Giúp mik đi hứa cho ctlhn Cho biết 4 x 552 : (x + 0,75) = 1,84 . Hãy tìm cách để đặt thêm một dấu phẩy vào chỗ nào đó trong đẳng thức trên để giá trị của x giảm 297 đơn vị .
Chỉ mik calli 5 chữ đầu tiên là a,b,c,d,e giống kiểu pic dưới
Cho góc xoy =100°.Tia Oz nằm trong góc xOy sao cho góc xOz =50°a)Tính số đo góc yOz. b)Tia Oz có phải là tia phân giác của góc xOy không?vì sao?
Task 2. Rewrite the following sentences as directed 1. It was such an expensive house that nobody can buy it. ⇒ The house was so ........ 2. The food was so good that we ate all of it. ⇒ It was ........ 3. The patient was too weak to get up. ⇒ The patient was so ........ 4. This room is too dark for me to study. ⇒ This room is so ........ 5. This room is too small for us to take the meeting ⇒ This room isn’t ........ 6. The test was so difficult that we couldn’t do it. ⇒ The test was not ........ 7. The map is so old that I couldn’t read it. ⇒ The map is too ........ 8. He spoke so fast that we couldn’t hear him well ⇒ He didn’t ........
Cho tam giác ABC có M là trung điểm của BC, trên tia đối của MA lấy điểm E sao cho ME = MA. Chứng minh: a/ tam giác MAB = tam giác MEC b/ AC song song với BE c/ Trên AB lấy điểm I, trên CE lấy K sao cho BI = CK. CMR I, M, K thẳng hàng vẽ hình hộ mik luôn nha
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