cứu với mn oi
K
Khách
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Những câu hỏi liên quan
DG
2
6 tháng 2 2022
\(=\frac{3}{2}\left(\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{5}+......+\frac{1}{99}-\frac{1}{100}\right).\)
\(=\frac{3}{2}.\left(\frac{1}{1}-\frac{1}{100}\right)=\frac{3}{2}.\frac{99}{100}=\frac{297}{200}\)
5 tháng 12 2021
Đk: x>0, x≠1
P=(√x/(√x -1) +√x/(√x +1)):√(4x)/(x-1)
P=((x+√x)/(x-1)+(x-√x)/(x-1)).(x-1)/√(4x)
P=(x+√x + x-√x)/(x-1).(x-1)/√(4x)
P=(2x)/(x-1).(x-1)/√(4x)
P=(2x)/√(4x)
P=√x
Vậy P=√x
AH
Akai Haruma
Giáo viên
2 tháng 1
Bài 5:
Với $x,y$ là số nguyên thì $x+1, xy-1$ cũng là số nguyên. Mà tích của chúng bằng 3 nên ta có các TH sau:
TH1: $x+1=1, xy-1=3\Rightarrow x=0; xy=3$ (vô lý - loại)
TH2: $x+1=-1, xy-1=-3\Rightarrow x=-2; xy=-2\Rightarrow y=1$ (thỏa mãn)
TH3: $x+1=3; xy-1=1\Rightarrow x=2; xy=2\Rightarrow y=1$ (thỏa mãn)
TH4: $x+1=-3; xy-1=-1\Rightarrow x=-4; xy=0$ (vô lý -loại)
Vậy......
AH
Akai Haruma
Giáo viên
2 tháng 1
Bài 6:
$\frac{a}{7}-\frac{1}{2}=\frac{1}{b+3}$
$\Rightarrow \frac{2a-7}{14}=\frac{1}{b+3}$
$\Rightarrow (2a-7)(b+3)=14$
Với $a,b$ nguyên thì $2a-7, b+3$ cũng là số nguyên. Mà $(2a-7)(b+3)=14$ và $2a-7$ là số nguyên lẻ nên ta các TH sau:
TH1: $2a-7=1; b+3=14\Rightarrow a=4; b=11$ (thỏa mãn)
TH2: $2a-7=-1; b+3=-14\Rightarrow a=3; b=-17$ (thỏa mãn)
TH3: $2a-7=7; b+3=2\Rightarrow a=7; b=-1$ (thỏa mãn)
TH4: $2a-7=-7; b+3=-2\Rightarrow a=0; b=-5$ (thỏa mãn)
NM
6
27 tháng 6
1.I think you ought to give up playing video games. (should)
-->I think you should give up playing video games.
2.It's necessary for me to finish the work on time. (have to)
--->I have to finish the work on time.
3.It wasn't necessary for you to clean that car. (have to)
--->You didn't have to clean that car.
4.It was quite unnecessary for you to adopt a green lifestyle. (have to)
---->You didn't have to adopt a green lifestyle.
5.It was careless of you to leave the windows open last night. (shouldn't)
----->You shouldn't have left the windows open last night.
6.It is advisable for each member in the family to share the housework equally. (should)
---->Each member in the family should share the housework equally.
7.You are required to come back home before 10 p.m. (must)
--->You must come back home before 10 p.m.
8.Lina is advised to prepare carefully in the morning. (should)
----->Lina should prepare carefully in the morning.
9.Tu is responsible for picking up litter. (have to)
------>Tu has to pick up litter.
27 tháng 6
1.You are required to ask your parents for permission before staying out late. (must)
You must ask your parents for permission before staying out late.
2.I think you ought to give up smoking immediately. (should)
I think you should give up smoking immediately.
3.It is not a good idea for me to stay up late. (shouldn't)
I shouldn't stay up late.
4.It wasn't necessary for you to send these letters. (have to)
You didn't have to send these letters.
5.It was unnecessary for Tim to finish the work. (have to)
Tim didn't have to finish the work.
6.It was careless of you to leave your children alone at home. (shouldn't)
You shouldn't have left your children alone at home.
Bằng 1 cách nào đó 1 câu hỏi từ 2023 ở đây và tôi vẫn trả lời nó sau 1 năm :v
Rewrite the sentences:
1. He allows me to go out at the weekend
→ He lets me go out at the weekend.
2. She is crazy about paiting ( like )
→ She likes painting a lot.
3. What about going to picnic next Sunday ?
→ Why don't we go for a picnic next Sunday ?
4. You shouldn't eat canned food.
→ You ought not to eat canned food.
5. Going in the rain is exciting
→ It's exhilarating to go in the rain.
6. It's interesting to go swimming in the summer
→ Going swimming in the summer is interesting.