bài toán : 8 tấm vải dài 800m hỏi 5 tấm vải dài bao nhiêu mét vải ?

bài giải

Một tấm vải dài số mét là :

800 / 8 = 100 (m)

5 tấm vải dài số mét là :

100 * 5 = 500 (m)

           ĐS: 500 m vải 

63% của 100 là :

  63 x 100 : 100 = 63 

vậy 63% của 100 là 63

bị điếc = hư tai = hai tư

Vậy đàn voi có 24 con

1. He is a strict .......examiner......................... . ( examine ).

2. I want to ..............attend.................. at course. ( attendance .

3. This school has excellenr ..........reputation...................... . ( repute )

4. We often take part in many ..........cultural...................... activities at school. ( culture )

5. If you want to .......improve......................... your English, we can help you. ( improvement )

6. Please phone this number for more ...imformation............................. . ( inform )

7. I want to ...............advertise................. for selling my house. ( advertisement )

8. He is an ................edition................ of this newpaper. ( edition )

9. This book is not ............available.................... . ( avail )

10. He ......................exactly.......... answered these question. ( exact )

bang 507 915 ban nhe

Ta có : \(\frac{n}{n+1}=\frac{n\left(n+3\right)}{\left(n+1\right)\left(n+3\right)}=\frac{n^2+3n}{n^2+3n+n+3}=\frac{n^2+3n}{n^2+4n+3}\)

             \(\frac{n+2}{n+3}=\frac{\left(n+2\right)\left(n+1\right)}{\left(n+3\right)\left(n+1\right)}=\frac{n^2+n+2n+2}{n^2+n+3n+3}=\frac{n^2+3n+2}{n^2+4n+3}\)

Vì  n² + 3n < n² + 3n + 2 => \(\frac{n^2+3n}{n^2+4n+3}<\frac{n^2+3n+2}{n^2+4n+3}\) =>  \(\frac{n}{n+1}<\frac{n+2}{n+3}\)

abc8+5778=8abc

abc x 10+8+5778=8000+abc

abc x 10-abc=8000-5778-8

abc x(10-1)=2214

abc x 9=2214

abc=2214:9

abc=246