Hệ số tỉ lệ k là \(k=\dfrac{y}{x}=\dfrac{8}{17}\)

 0,117 mol ion H+

1 Why did you have to go to school last Saturday
2 You shouldn't spend too much time playing games
3 The children must wear a uniform
4 You should say sorry to your parents
5 You shouldn't drink so much coffee
6 He doesn't have to apologize. He was absolutely right
7 We have to give him our answer today or we'll lose out on the contract
8 You should go and lie down
9 You don't have to learn all the new words
10 Do you have to attend every English lesson
11 Harry should take a holiday
12 You shouldn't leave a child unsupervised
13 You have to register in advance to take the course
14 You don't have to read all those books
15 You should spend more time with her

Em mik nó đang cố vào trường THCS Marie Curie , mik chúc nó không thành công , há há .

Học giỏi vậy, cấp 1 em bn học trường nào v?

\(A=5+5^2+5^3+\dots+5^{200}\\5A=5^2+5^3+5^4+\dots+5^{201}\\5A-A=(5^2+5^3+5^4+\dots+5^{201})-(5+5^2+5^3+\dots+5^{200})\\4A=5^{201}-5\\\Rightarrow A=\frac{5^{201}-5}{4}\)

A = 5 + 5² + 5³ + ... + 5²⁰⁰

⇒ 5A = 5² + 5³ + 5⁴ + ... + 5²⁰¹

⇒ 4A = 5A - A

= (5² + 5³ + 5⁴ + ... + 5²⁰¹) - (5 + 5² + 5³ + ... + 5²⁰⁰)

= 5²⁰¹ - 5

2.(6 + 94) . 21 - (12 - 7)²

= 2.100.21 - 5²

= 4200 - 25

= 4175

4 tấn 365kg=4365kg

Khối lượng cá thu là: \(4365\times\dfrac{2}{1+2}=4365\times\dfrac{2}{3}=2910\left(kg\right)\)

Tổng khối lượng cá chim và cá đuối là:

4365-2910=1455(kg)

Khối lượng cá đuối là: \(1455\times\dfrac{3}{2+3}=1455\times\dfrac{3}{5}=873\left(kg\right)\)

Khối lượng cá chim là:

1455-873=582(kg)

18 nhé bạn