Mk có bài khó ,ai bt lm giúp mk nha :D .Mk đang cần gấp
Cho a,b,c>0 ,CMr : 1<a/(a+b) +b/(b+c) +c/(c+a) <2 Cho x,y<0 CMr : x^2/y^2+y^2/x^2 > hoặc =x/y+y/xGiải giúp tôi vs m.n :'(
có ai bt lm bài này ko giúp mk vs mk đang cần rất rất gấp mong các bsnj giúp cho
Bài 1:
a: \(\sqrt{0.49a^2}=-0.7a\)
b: \(\sqrt{25\left(a-7\right)^2}=5a-35\)
c: \(\sqrt{a^4\left(a-2\right)^2}=a^2\cdot\left(a-2\right)\)
d: \(\dfrac{1}{a-3b}\cdot\sqrt{a^6\left(a-3b\right)^2}\)
\(=\dfrac{1}{a-3b}\cdot a^3\cdot\left(a-3b\right)=a^3\)
Bài 2:
a: \(2\left(x+y\right)\cdot\sqrt{\dfrac{1}{x^2+2xy+y^2}}\)
\(=2\left(x+y\right)\cdot\dfrac{1}{x+y}\)
=2
b: \(\dfrac{3x}{7y}\cdot\sqrt{\dfrac{49y^2}{9x^2}}\)
\(=\dfrac{3x}{7y}\cdot\dfrac{-7y}{3x}\)
=-1
\(1,\\ a,\sqrt{0,49a^2}\left(a< 0\right)=-0,7a\\ b,\sqrt{25\left(7-a\right)^2}\left(a\ge7\Leftrightarrow7-a\le0\right)=5\left(a-7\right)\\ c,\sqrt{a^4\left(a-2\right)^2}\left(a>0\right)=\left[{}\begin{matrix}a^2\left(a-2\right),\forall a\ge2\\a^2\left(2-a\right),\forall0< a< 2\end{matrix}\right.\\ d,\dfrac{1}{a-3b}\sqrt{a^6\left(a-3b\right)^2}\left(a>3b>0\right)=\dfrac{1}{a-3b}\cdot a^3\left(a-3b\right)=a^3\)
có ai bt lm bài này k giúp mk vs mk đang cần rất rất gấp mong các bạn giúp cho
Có ai bt lm bài này không giúp mk vs mk đg cần rất rất gấp mong các bn lm cho Bài này chỉ là bài lớp 6 thui nha
1 My parents go shopping twice a week
2 Hoa's house has a balcony
3 My brother usually plays badminton with his friends
4 My favorite book is Tam and Cam. What is yours?
5 There are 10 pencil cases on the table
1, My parents go shopping twice a week.
2, Hoa's house has a balcony.
3, My brother usually plays badminton with his friends.
4, My favorite book is Tam and Cam. What's yours?
5, There are ten pencil cases on the table.
có ai bt giải bài này k giúp mk vs mk đg cần rất rất gấp mong các bn giúp cho( lm VD1 vs VD2 thôi nha)
Có ai bt lm bài này k giúp mk vs mk đang rất rất cần mong các bn giúp cho
a.
- Thử với lượng nhỏ mỗi chất.
dd HCl | dd H2SO4 | |
dd BaCl2 | Không hiện tượng | Kết tủa trắng |
\(H_2SO_4+BaCl_2\rightarrow BaSO_4\downarrow\left(trắng\right)+2HCl\)
b.
- Thử với lượng nhỏ mỗi chất.
dd KCl | dd K2SO4 | |
dd BaCl2 | Không hiện tượng | Kết tủa trắng |
\(K_2SO_4+BaCl_2\rightarrow BaSO_4\downarrow\left(trắng\right)+2KCl\)
c.
a.
- Thử với lượng nhỏ mỗi chất.
dd K2SO4 | dd H2SO4 | |
Qùy tím | Không đổi màu | Hóa đỏ |
có ai bt lm bài này k giúp mk vs mk đg rất rất cần gấp mong các bn giúp cho
1 was arrested before the garden by the boy yesterday
2 his cats taken care of carefully by Jack everyday
3 Has the country been protected from Covid-19 successfully
4 is reported that the man is running out of money
is reported to be running out of money\
5 has been said that the thief got out of the prison
has been said to have got out of the prison
6 was thought that Mary had turned down the job
Mary was thought to have turned down the job
có ai bt lm bài này k giúp mk vs mk đg cần rất rất gấp mong các bạn giúp cho
\(1,\\ a,=\dfrac{\left(3+2\sqrt{3}\right)\sqrt{3}}{3}+\dfrac{\left(2+\sqrt{2}\right)\left(\sqrt{2}-1\right)}{1}\\ =\dfrac{3\sqrt{3}+6}{3}+\sqrt{2}=\sqrt{3}+1+\sqrt{2}\\ b,=\left(\dfrac{\sqrt{5}+\sqrt{2}}{3}-\dfrac{\sqrt{5}-\sqrt{2}}{3}+1\right)\cdot\dfrac{1}{\left(\sqrt{2}+1\right)^2}\\ =\dfrac{\sqrt{5}+\sqrt{2}-\sqrt{5}+\sqrt{2}+3}{3}\cdot\dfrac{1}{\left(\sqrt{2}+1\right)^2}\\ =\dfrac{2\sqrt{2}+3}{3\left(3+2\sqrt{2}\right)}=\dfrac{1}{3}\)
\(2,\\ A=2x+\sqrt{\left(x-3\right)^2}=2x+\left|x-3\right|\\ =2\left(-5\right)+\left|-5-3\right|=-10+8=-2\\ B=\dfrac{\sqrt{\left(2x+1\right)^2}}{\left(x-4\right)\left(x+4\right)}\left(x-4\right)^2=\dfrac{\left|2x+1\right|\left(x-4\right)}{x+4}\\ B=\dfrac{17\cdot4}{12}=\dfrac{17}{3}\)
có ai bt lm bài này k giúpmk vs mk đang cần rất rất gấp mong các bn giúp cho
Bài 1:cho tam giác ABC vuông tại A , đường cao cho BH= 16cm , CH=25cm. Tính góc B, Góc C , tính cạnh AB, AC
Tối thiểu em phải ghi đúng đề ra chứ. Đường cao là đường cao nào? H là điểm nào? Đó là những chi tiết trong đề còn thiếu
Có ai bt lm bài này k giúp mk vs mk đang rất rất cần mong các bn giúp cho II/ ChooseA, B, C, D for each gap in the following sentences 3. Osaka has become one of the...........“liveable" city in Asia. A. more B. better C. much D. most 4.The traditional craft hasfrom generation to generation. A. passed down B. passed C. been passed down D. been passed by 5.The Van Phuc producers silk have expanded their silk garment goodsthey can satisfy the varied demand for their silk. A. in order to B. despite C. because D. so that 6. ___________ they moved to the city five years ago, they still remember living in a small town. A. Although B. Whereas C. While D. In order that 7.This company has gone bankrupt. Do you know who will_________ ? A. take care of it B. look after it C. take it over D. turn it up 8.The people in my village cannot earn enough money for their daily life. They can't______ this traditional craft. They have to find other jobs. A. help out B. live on C. work on D. set up 9 .Peter and Jane said to me: “Our wedding will be held next week”. A.Peter and Jane said to me that my wedding would be held next week. B.Peter and Jane said to me that their wedding would be held the next week. C.Peter and Jane said to me that their wedding would be held the following week D. Peter and Jane said me that their wedding would be held the following week
ChooseA, B, C, D for each gap in the following sentences 3. Osaka has become one of the...........“liveable" city in Asia. A. more B. betterC. much D. most 4.The traditional craft hasfrom generation to generation.A. passed down B. passedC. been passed down D. been passed by 5.The Van Phuc producers silk have expanded their silk garment goods they can satisfy the varied demand for their silk. A. in order to B. despiteC. because D. so that 6. ___________ they moved to the city five years ago, they still remember living in a small town. A. Although B. WhereasC. While D. In order that 7.This company has gone bankrupt. Do you know who will_________ ? A. take care of it B. look after itC. take it over D. turn it up 8.The people in my village cannot earn enough money for their daily life. They can't______ this traditional craft. They have to find other jobs. A. help outB. live onC. work onD. set up 9 .Peter and Jane said to me: “Our wedding will be held next week”. A.Peter and Jane said to me that my wedding would be held next week. B.Peter and Jane said to me that their wedding would be held the next week. C.Peter and Jane said to me that their wedding would be held the following week D. Peter and Jane said me that their wedding would be held the following week