làm dc câu nào thì làm nhé lm hết thì càng tốt
K
Khách
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
HT
1
Những câu hỏi liên quan
25 tháng 1 2022
a) \(\left(-23\right)+230+23=0+230=230.\)
b) \(124.\left(-54\right)+24.54=54.\left(-124+24\right)=54.\left(-100\right)=-5400.\)
c) \(-927+1421+930+\left(-1421\right).\)
\(=-927+930=3.\)
25 tháng 1 2022
a) (-23) + 230 + 23 =230
b) 124 . (-54) + 24 . 54 =− 5400.
c) -927 + 1421 + 930 + (-1421) =3.
d) (-351) + (-74) + 51 + (-126) + 149=-351
TN
1
6 tháng 2 2022
1. How => When
2. Why => How
3. How much => Why
4. Where => What
5. What time => How many days
6. Whom => Whose
7. What => Which
8. Why => Where
9. How => Who
10. Who => What
11. Where => When
12. When => Why
13. Why => How
14. How much => How long
15. Where => How far
N
2
DT
Đỗ Thanh Hải
CTVVIP
3 tháng 8 2021
10. ……………. festival do you choose? - I choose Elephant Race Festival.
A. What B. How C. Which D. When
11. ……………. often is Burning Festival held? - It's held every year.
A. Which B. When C. What D. How
12. ……………. does the teacher say La Tomatina sounds unusual? - Because people throw tomatoes at each other for one hour at the festival.
A. What B. When C. Why D. How
13. He ___________ books for poor children for years.
A. has collected B. collects C. is collecting D. collected
14. Next Saturday at this time, we _____ on the beach in Mexico.
A. will relax B. will be relaxing C. has relaxed D. relax
15. Anne and Joe _____ by sea tomorrow
A. travel B. will travel C. travels D. travelled
16. I_____ in Jakarta, but now I live in New York. [use to + V-inf]
A. used to living B. used to living C. used to live D. am used to live
17. Jane_____ for the telephone company, but now she has a job at the post office.
A. used to working B. used to worked C. is used to work D. used to work
18. …………. he spent much money on the film, it wasn't a big success.
A. Even B. But C. Although D. Despite
19. We didn't find it funny………..it was a comedy.
A. in spite of B. despite C. although D. but
20. I went to the cinema with my friends yesterday ………… feeling very tired.
A. although B. in spite C. despite D. but
21. Let's go to the Victor Cinema. I'm sure you'll find the film…………
A. excites B. excite C. excited D. exciting
22. I was ……… to learn that the director of that gripping film has won the first prize.
A. interest B. interests C. interested D. interesting
23. The film was boring, ____ we went home.
A. so B. when C. but D. if
24. Nam was absent from class yesterday ____ he felt sick.
A. so B. because C. although D. but
25. These books aren’t yours, ____________?
A.are these B. aren’t these C. are they D. aren’t they
26. No one died in the accident, ______________?
A.did they B. didn’t they C. did he D. didn’t he
27. Tom knows Alice, _____________?
A.doesn’t he B. is he C. does he D. isn’t he
28. Peter never comes to class late, ________________?
A. doesn’t he B. doesn’t Peter C. does he D. does Peter
29. ……… computer is a laptop, but ……… is a desktop.
A. Hers - you B. Her - your C. My - yours D. Mine - yours
30. We gave them ……… ID number, and they gave us ……….
A. ours - theirs B. our - theirs C. our -their D. ours - their
KY
3 tháng 8 2021
Mn giúp mik ak câu nào mn bt thì lm còn lm hết đc thì càng tốt nhé TKS
10. ……………. festival do you choose? - I choose Elephant Race Festival.
A. What B. How C. Which D. When
11. ……………. often is Burning Festival held? - It's held every year.
A. Which B. When C. What D. How
12. ……………. does the teacher say La Tomatina sounds unusual? - Because people throw tomatoes at each other for one hour at the festival.
A. What B. When C. Why D. How
13. He ___________ books for poor children for years.
A. has collected B. collects C. is collecting D. collected
14. Next Saturday at this time, we _____ on the beach in Mexico.
A. will relax B. will be relaxing C. has relaxed D. relax
15. Anne and Joe _____ by sea tomorrow
A. travel B. will travel C. travels D. travelled
16. I_____ in Jakarta, but now I live in New York. [use to + V-inf]
A. used to living B. used to living C. used to live D. am used to live
17. Jane_____ for the telephone company, but now she has a job at the post office.
A. used to working B. used to worked C. is used to work D. used to work
18. …………. he spent much money on the film, it wasn't a big success.
A. Even B. But C. Although D. Despite
19. We didn't find it funny………..it was a comedy.
A. in spite of B. despite C. although D. but
20. I went to the cinema with my friends yesterday ………… feeling very tired.
A. although B. in spite C. despite D. but
21. Let's go to the Victor Cinema. I'm sure you'll find the film…………
A. excites B. excite C. excited D. exciting
22. I was ……… to learn that the director of that gripping film has won the first prize.
A. interest B. interests C. interested D. interesting
23. The film was boring, ____ we went home.
A. so B. when C. but D. if
24. Nam was absent from class yesterday ____ he felt sick.
A. so B. because C. although D. but
25. These books aren’t yours, ____________?
A.are these B. aren’t these C. are they D. aren’t they
26. No one died in the accident, ______________?
A.did they B. didn’t they C. did he D. didn’t he
27. Tom knows Alice, _____________?
A.doesn’t he B. is he C. does he D. isn’t he
28. Peter never comes to class late, ________________?
A. doesn’t he B. doesn’t Peter C. does he D. does Peter
29. ……… computer is a laptop, but ……… is a desktop.
A. Hers - you B. Her - your C. My - yours D. Mine - yours
30. We gave them ……… ID number, and they gave us ……….
A. ours - theirs B. our - theirs C. our -their D. ours - their
7 tháng 7 2016
a) \(\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+...+\frac{1}{98.99}+\frac{1}{99.100}\)\(=\left(1-\frac{1}{2}\right)+\left(\frac{1}{2}-\frac{1}{3}\right)+\left(\frac{1}{3}-\frac{1}{4}\right)+...+\left(\frac{1}{98}-\frac{1}{99}\right)+\left(\frac{1}{99}-\frac{1}{100}\right)\)
\(=1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{98}-\frac{1}{99}+\frac{1}{99}-\frac{1}{100}\)
\(=1-\frac{1}{100}=\frac{99}{100}\)
b) \(\frac{1}{6}+\frac{1}{12}+\frac{1}{20}+...+\frac{1}{90}+\frac{1}{110}\)\(=\frac{1}{2.3}+\frac{1}{3.4}+...+\frac{1}{9.10}+\frac{1}{10.11}\)
\(=\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+\frac{1}{5}...+\frac{1}{9}-\frac{1}{10}+\frac{1}{10}-\frac{1}{110}\)
\(=\frac{1}{2}-\frac{1}{100}=\frac{49}{100}\)
c) \(\frac{2}{11.13}+\frac{2}{13.15}+\frac{2}{15.17}+...+\frac{2}{97.99}\) \(=\frac{13-11}{11.13}+\frac{15-13}{13.15}+\frac{17-15}{15.17}+...+\frac{99-97}{97.99}\)
\(=\frac{1}{11}+\frac{1}{13}-\frac{1}{13}+\frac{1}{15}-\frac{1}{15}+\frac{1}{17}...+\frac{1}{97}-\frac{1}{99}\)
\(=\frac{1}{11}-\frac{1}{99}=\frac{8}{99}\)
3 tháng 10 2021
ta có Cu ko tác dụng được vs H2SO4
-> 2,24 lít khí H2 đc tạo ra là do phản ứng HH của Fe va H2SO4
\(PTHH:\) \(Fe+H_2SO_4->FeSO_4+H2\)
n H2 = 2,24 :22,4=0,1 mol
n H2 = n Fe =0,1 mol
m Fe = 0,1.56=5,6 g
m Cu = 10-5,6=4,4 g
vậy giá trị của x là 4,4 g
3 tháng 10 2021
26
PTHH : \(Zn+2HCl->ZnCl_2+H_2\)
n Zn = 6,5:65=0,1 mol
n ZnCl2 = n Zn =0,1 mol
m ZnCl2 = 0,1.(65+35,5.2)=13,6 g
11 tháng 8 2020
a)
<=> \(3x-12x^2+12x^2-6x=9\)
<=> \(-3x=9\)
<=> \(x=-3\)
b)
<=> \(6x-24x^2-12x+24x^2=6\)
<=> \(-6x=6\)
<=> \(x=-1\)
c)
<=> \(6x-4-3x+6=1\)
<=> \(3x+2=1\)
<=> \(x=-\frac{1}{3}\)
d)
<=> \(9-6x^2+6x^2-3x=9\)
<=> \(-3x=0\)
<=> \(x=0\)
e) KO HIỂU ĐỀ
f)
<=> \(4x^2-8x+3-\left(4x^2+9x+2\right)=8\)
<=> \(-17x+1=8\)
<=> \(x=-\frac{7}{17}\)
g)
<=> \(-6x^2+x+1+6x^2-3x=9\)
<=> \(-2x=8\)
<=> \(x=-4\)
h)
<=> \(x^2-x+2x^2+5x-3=4\)
<=> \(3x^2+4x=7\)
<=> \(\orbr{\begin{cases}x=1\\x=-\frac{7}{3}\end{cases}}\)
KN
11 tháng 8 2020
a. \(3x\left(1-4x\right)+6x\left(2x-1\right)=9\)
\(\Rightarrow3x-12x^2+12x^2-6x=9\)
\(\Rightarrow-3x=9\)
\(\Rightarrow x=-3\)
b. \(3x\left(2-8x\right)-12x\left(1-2x\right)=6\)
\(\Rightarrow6x-24x^2-12x+24x^2=6\)
\(\Rightarrow-6x=6\)
\(\Rightarrow x=-1\)
c. \(2\left(3x-2\right)-3\left(x-2\right)=1\)
\(\Rightarrow6x-4-3x+6=1\)
\(\Rightarrow3x+2=1\)
\(\Rightarrow3x=-1\)
\(\Rightarrow x=-\frac{1}{3}\)
15 tháng 5 2016
thế thì mình làm bài 2 và bài 3 ở trang đầu:
Bài 2: A; C
Bài 3: A; C
LP
2
4 tháng 9 2021
\(7,x^4+x^3+x^2-1=x^3\left(x+1\right)+\left(x-1\right)\left(x+1\right)=\left(x^3+x-1\right)\left(x+1\right)\)
\(8,x^2y^2+1-x^2-y^2=\left(x^2y^2-y^2\right)-\left(x^2-1\right)\\ =y^2\left(x^2-1\right)-\left(x^2-1\right)=\left(x-1\right)\left(x+1\right)\left(y-1\right)\left(y+1\right)\)
\(10,x^4-x^2+2x-1=x^4-\left(x-1\right)^2=\left(x^2-x+1\right)\left(x^2+x-1\right)\\ 11,3a-3b+a^2-2ab+b^2=3\left(a-b\right)+\left(a-b\right)^2=\left(3+a-b\right)\left(a-b\right)\\ 12,a^2+2ab+b^2-2a-2b+1=\left(a+b\right)^2-2\left(a+b\right)+1=\left(a+b-1\right)^2\\ 13,a^2-b^2-4a+4b=\left(a-b\right)\left(a+b\right)-4\left(a-b\right)=\left(a+b-4\right)\left(a-b\right)\\ 14,a^3-b^3-3a+3b=\left(a-b\right)\left(a^2+ab+b^2\right)-3\left(a-b\right)=\left(a-b\right)\left(a^2+ab+b^2-3\right)\\ 15,x^3+3x^2-3x-1=\left(x-1\right)\left(x^2+x+1\right)+3x\left(x-1\right)=\left(x-1\right)\left(x^2+4x+1\right)\)
4 tháng 9 2021
1)
=0,25y.(64x3+z3)
2)
=x2(x2-4x+4)
=x2(x-2)2
5)
=x2(x+1)-4(x+1)
=(x2-4)(x+1)
=(x-2)(x+2)(x+1)
6)
=x2(x-1)-(x-1)
=(x2-1)(x-1)
=(x-1)(x+1)(x-1)
=(x-1)2(x+1)
A
2
tiếng anh lớp 8 nha