có tổng cộng 15 cái kẹo và 21 bạn.

a: \(\dfrac{3}{5}+3\dfrac{5}{6}\left(11\dfrac{5}{20}-9\dfrac{1}{4}\right):7\dfrac{2}{3}\)

\(=\dfrac{3}{5}+\dfrac{23}{6}\left(11+\dfrac{5}{20}-9-\dfrac{1}{4}\right):\dfrac{23}{3}\)

\(=\dfrac{3}{5}+\dfrac{23}{6}\cdot2\cdot\dfrac{3}{23}=\dfrac{3}{5}+1=\dfrac{8}{5}\)

b: \(\dfrac{7}{13}\cdot\dfrac{7}{15}-\dfrac{1}{3}\cdot\dfrac{21}{39}+\dfrac{49}{91}\cdot\dfrac{8}{15}\)

\(=\dfrac{7}{13}\cdot\dfrac{7}{15}-\dfrac{1}{3}\cdot\dfrac{7}{13}+\dfrac{7}{13}\cdot\dfrac{8}{15}\)

\(=\dfrac{7}{13}\left(\dfrac{7}{15}+\dfrac{8}{15}-\dfrac{1}{3}\right)=\dfrac{7}{13}\cdot\dfrac{2}{3}=\dfrac{14}{39}\)

c: \(\left(1-\dfrac{1}{2}\right)\left(1-\dfrac{1}{3}\right)\cdot...\cdot\left(1-\dfrac{1}{2023}\right)\)

\(=\dfrac{1}{2}\cdot\dfrac{2}{3}\cdot...\cdot\dfrac{2022}{2023}\)

\(=\dfrac{1}{2023}\)

d: \(\dfrac{2}{4\cdot5}+\dfrac{2}{5\cdot6}+...+\dfrac{2}{99\cdot100}\)

\(=2\left(\dfrac{1}{4\cdot5}+\dfrac{1}{5\cdot6}+...+\dfrac{1}{99\cdot100}\right)\)

\(=2\left(\dfrac{1}{4}-\dfrac{1}{5}+\dfrac{1}{5}-\dfrac{1}{6}+...+\dfrac{1}{99}-\dfrac{1}{100}\right)\)

\(=2\left(\dfrac{1}{4}-\dfrac{1}{100}\right)=2\cdot\dfrac{24}{100}=\dfrac{48}{100}=\dfrac{12}{25}\)

e: \(\dfrac{3}{1\cdot3}+\dfrac{3}{3\cdot5}+...+\dfrac{3}{99\cdot101}\)

\(=\dfrac{3}{2}\left(\dfrac{2}{1\cdot3}+\dfrac{2}{3\cdot5}+...+\dfrac{2}{99\cdot101}\right)\)

\(=\dfrac{3}{2}\left(1-\dfrac{1}{3}+\dfrac{1}{3}-\dfrac{1}{5}+...+\dfrac{1}{99}-\dfrac{1}{101}\right)\)

\(=\dfrac{3}{2}\left(1-\dfrac{1}{101}\right)=\dfrac{3}{2}\cdot\dfrac{100}{101}=\dfrac{150}{101}\)

f: \(\dfrac{10}{3\cdot6}+\dfrac{10}{6\cdot9}+...+\dfrac{10}{96\cdot99}\)

\(=\dfrac{10}{3}\left(\dfrac{3}{3\cdot6}+\dfrac{3}{6\cdot9}+...+\dfrac{3}{96\cdot99}\right)\)

\(=\dfrac{10}{3}\left(\dfrac{1}{3}-\dfrac{1}{6}+\dfrac{1}{6}-\dfrac{1}{9}+...+\dfrac{1}{96}-\dfrac{1}{99}\right)\)

\(=\dfrac{10}{3}\left(\dfrac{1}{3}-\dfrac{1}{99}\right)=\dfrac{10}{3}\cdot\dfrac{32}{99}=\dfrac{320}{297}\)

a. Năng suất = Sản lượng / Diện tích

b. Vẽ biểu đồ kết hợp (cột đường), sản lượng là cột, năng suất là đường.

tại ruộng lúa

Trồng trọt phát triển chủ yếu trên đảo Hô-cai-đô (Nhật Bản).

a) \(P\left(x\right)+Q\left(x\right)=x^4-2x^2+1\)

\(\Rightarrow Q\left(x\right)=x^4-2x^2+1-P\left(x\right)\)

\(=x^4-2x^2+1-\left(x^3-2x^2+x-\dfrac{1}{2}\right)\)

\(=x^4-2x^2+1-x^3+2x^2-x+\dfrac{1}{2}\)

\(=x^4-x^3+\left(-2x^2+2x^2\right)-x+\left(1+\dfrac{1}{2}\right)\)

\(=x^4-x^3-x+\dfrac{3}{2}\)

b) \(P\left(x\right)-H\left(x\right)=x^3+x^2+2\)

\(\Rightarrow H\left(x\right)=P\left(x\right)-\left(x^3+x^2+2\right)\)

\(=\left(x^3-2x^2+x-\dfrac{1}{2}\right)-\left(x^3+x^2+2\right)\)

\(=x^3-2x^2+x-\dfrac{1}{2}-x^3-x^2-2\)

\(=\left(x^3-x^3\right)+\left(-2x^2-x^2\right)+x+\left(-\dfrac{1}{2}-2\right)\)

\(=-3x^2+x-\dfrac{5}{2}\)

Bạn nào giải hộ mình vs

1: My full name is Nguyen Le Phuoc Thinh.

2: I live in Ho Chi Minh city.

3: My ethnicity is Kinh.

4: I often use smartphone.

5: I use for working

1. My name is Nguyen Duc Huy

2. I live in Bac Giang

3. My ethnicity is Kinh

4. I often use tablet devices

5. I use for study

1.My telescope doesn't work as well as hers does.

2.While I was walking to school yesterday, I saw Emily crying in the hallway.

3.Two of her classmates want to become doctors when they grow up.

1 Her telescope works better than mine

2 While I was walking to school yesterday, I saw Emily crying in the hallway

3 Two classmates of her want to become doctors when they grow up