1 When we were in Canada, we went(go) skiing almost every day
2 When did you meet((you/meet) you wife? - 3 years ago
3 Peter hasn't phoned(not phone) yet. I'm still waiting
4 I have known(know) Helen since we were at school together
5 My uncle lived(live) in Berlin in 1999
6 We didn't see(not see) Beth at Mike's house yesterday morning
7 Do you like this picture? My uncle has just painted(paint) it
8 Mr Dass left (leave) for New York late last night
9 Mr and Mrs Grey have taught (teach) French here for over five years

Đề bài phải là tìm giá trị nhỏ nhất nhé ^^

Ta có ; \(B=\frac{x^2+x+1}{x^2+2x+1}=\frac{x^2+x+1}{\left(x+1\right)^2}\)

Đặt y = x+1 => x = y-1 \(\Rightarrow B=\frac{\left(y-1\right)^2+\left(y-1\right)+1}{y^2}=\frac{y^2-y+1}{y^2}=\frac{1}{y^2}-\frac{1}{y}+1\)

Đặt \(t=\frac{1}{y}\Rightarrow B=t^2-t+1=\left(t-\frac{1}{2}\right)^2+\frac{3}{4}\ge\frac{3}{4}\)

Vậy Min B = \(\frac{3}{4}\Leftrightarrow t=\frac{1}{2}\Leftrightarrow y=2\Leftrightarrow x=1\)

1. He sells cars.

2. The blue car is sold.

3. In summer, more ice-cream is eaten than in winter.

4. She calls her grandparents every Friday.

5. The letters are typed.

6. He takes his medicine every day.

7. Jane is not taken to school by her father.

8. We go to school by bus.

9. She does not work for a bank.

10. Milk is kept in the refrigerator

cảm ơn bạn nhiều

\(A=\frac{1}{20}+\frac{1}{30}+\frac{1}{42}+...+\frac{1}{990}\)

   \(=\frac{1}{4.5}+\frac{1}{5.6}+\frac{1}{6.7}+...+\frac{1}{30.31}\)

    \(=\frac{1}{4}-\frac{1}{5}+\frac{1}{5}-\frac{1}{6}+....+\frac{1}{30}-\frac{1}{31}\)

      \(=\frac{1}{4}-\frac{1}{31}\)

      \(=\frac{27}{124}\)

2+1=3

k cho mk nhoa

viết 1 đoạn văn 7 đến 10 câu (nội dung tự chọn) trong đoạn văn có sử dụng ít nhất 3 từ Hán Việt và 3 quan hệ từ

chép bài nhau à sao j thế

G (x) = x² + 2x + 3

= x² + x + x + 1 + 2

= x.(x + 1) + (x + 1) + 2

= (x + 1).(x + 1) + 2

= (x + 1)² + 2 \(\ge\)2

Vậy G(x) vô nghiệm.

A (x) = x² - x + 1

= x² - 1/2x - 1/2x + 1/4 + 3/4

= x.(x - 1/2) - 1/2.(x - 1/2) + 3/4

= (x - 1/2).(x - 1/2) + 3/4

= (x - 1/2)² + 3/4 \(\ge\)3/4

Vậy A(x) vô nghiệm.

Nếu xóa chữ số 1 ở bê trái số lớn có 4 chữ số thì được số bé. Vậy số lớn hơn số bé 1000 đơn vị.

      Số lớn là :

        ( 2906 + 1000 ) : 2 = 1953

      Số bé là :

             1953 - 1000 = 953

                 Đáp số : Số lớn  : 1953

                              Số bé : 953