Chiều dài của hình lập phương đó là 9cm

Số chân của 322 con gà có 10 chân là :

       322 x 10 = 3220 ( chân )

Số chân các con gà còn lại là :

       ( 500 - 322) x 2 = 356 ( chân )

Số chân của 20 con lợn là :

       20 x 4 = 80 ( chân )

Số chân có tất cả là :

       3220 + 356 + 80 = 3656 ( chân )

                    Đáp số 3656 chân

tớ thấy đáp án là 4 hợp lí hơn

dư nghĩa là thừa

nên a=95

95 : 91=1 (du 4)

Vậy số dư là 4

x + 3 chia hết cho x - 1

=> x - 1 + 4 chia hết cho x - 1

Mà x - 1 chia hết cho x - 1

=> 4 chia hết cho x - 1

=> x - 1 thuộc Ư(4) = {-4; -2; -1; 1; 2; 4}

=> x thuộc {-3; -1; 0; 2; 3; 5}.

nhìn vào ta thấy :

thùng 1      4 phần

thùng 2       6 phần

thùng 3       5 phần

thùng thứ nhất có số lít là :

45 : (4+6+5) x 4 = 12

thùng thứ 2 có số l là : 

 45 : (4+6+5) x 6 = 18

thùng thứ 3 có số l là : 

 45 : (4+6+5) x 5 = 15

Đs : ..

mình lớp 4 còn giải đc

Giải:

Ta có: \(-7\le x\le7\)

\(x\in\left\{-7;-6;-5;-4;-3;-2;-1;0;1;2;3;4;5;6;7\right\}\)

Tổng các số nguyên x là:

\(\left(-7\right)+\left(-6\right)+\left(-5\right)+\left(-4\right)+\left(-3\right)+\left(-2\right)+\left(-1\right)+0+1+2+3+4+5+6+7=0\)

Vậy ...

1. Talking to you is very interesting.
->It.......is very interesting to talk to you..........................................
2. The last time we visited Xich Dang Temple of Literature was 3 months ago.
-> We haven't........................visited X.D Temple of Literature for 3 months.............................................................................
3. The problem was so difficult that I couldn't understand it.
-> The problem was too......................difficult for me to understand .............................
4. Did they return those books to the library?
-> Were.........those books returned to the library?......................................
5. Because she behaves well, everybody loves her.
-> Because of....... her good behaviour, everybody loves her................................................
6. ''Where are you going next weekend?'' Linh said to Trung.
-> Linh asked.......Trung where he was going the next/ following weekend........
7. They think the owner if the restaurant is abroad.
-> The owner.........of the house is thought to be abroad............................................
8. He worked so hard that he forgot his lunch.
-> So hard..............did he worked that he forgot his lunch.........................................
9. Both of the chairs are uncomfortable.
-> Neither of...........the chairs is comfortable...............................
10. He told his customer: ''Please bring it back if it doesn't fit well."
-> He told........his customer to bring it back if it didn't fit well..........................................................................

I.
1. I only recognised him ..... the way he spoke
A. By
B. In
C. With
D. Of
2. I met Smith yesterday, but I knew him long .... that
A.for
B.by
C.before
D. After
3. I think he can make a success...music
A.to
B.in
C.with
D.of
4. He wrote... a fountain pen
A.with
B.by
C.for
D.in
5. Go and sit .... Richard
A beside
B. Next to
C. By
D. All are correct
6. Stand.... front of me you will see better ; there will be nothing...the way of you view
A. At / in
B. In/ of
C.In/ in
D. In/ at
7. It gets... when the winter is coming
A. Cold and cold
B. The coldest and coldest
C. Colder and colder
D. More and more cold
II.
You've probably known about computers your whole life. But computers have not really been around for very long. Computers started to become ...(1)... with big companies in the 1960s. Computers didn't become widespread in homes and schools...(2)... the 1980s.
Computers need hardware and ...(3)... in order to work. Your desktop or laptop and all the parts inside... (4)... hardware. The central processing unit(CPU) makes the computer.... (5)... The keyboard, mouse, printer, and monitor are also pieces of computer hardware. Memory chips are hardware that stores....(6)... and instructions. Information also gets stored on the hard disk drive. The programs ....(7)... run the computer are called software. The computer operating system is software that tells the computer how to run. Application or programs are software that do certain tasks. Word- processing programs, ....(8).... exampe, let you write school report and letter
(1). A. Populary B. Popular C. Popularity D. Popularities
(2) A. As B. Until C. When. D. While
(3). A. Har B.soft. C.software D.hardware
(4) A.are called B.called C.is called D.calling
(5) A. Work . B.wor . C. To work. D.working
(6) A.informing B. Informative C. Information D. Inform
(7) A.that. B. Who. C. Whom. D. Whose
(8) A. About B.over. C. At. D. For
III. Tham khảo pic dưới đây nhé

Giải:

\(\dfrac{1}{a}+\dfrac{1}{b}+\dfrac{1}{c}=\dfrac{1}{a+b+c}\)

\(\Leftrightarrow\dfrac{1}{a}+\dfrac{1}{b}+\dfrac{1}{c}-\dfrac{1}{a+b+c}=0\)

\(\Leftrightarrow\dfrac{a+b}{ab}+\dfrac{1}{c}-\dfrac{1}{a+b+c}=0\)

\(\Leftrightarrow-\dfrac{a+b}{ab}-\dfrac{1}{c}+\dfrac{1}{a+b+c}=0\)

\(\Leftrightarrow-\dfrac{a+b}{ab}-\dfrac{a+b}{c\left(a+b+c\right)}=0\)

\(\Leftrightarrow\left(a+b\right)\left(\dfrac{1}{ab}+\dfrac{1}{ac+bc+c^2}\right)=0\)

\(\Leftrightarrow\left(a+b\right)\left(b+c\right)\left(c+a\right)=0\)

Vậy ...

235/5 = 235 : 5 = 47