Известно,что график функции y=k/x проходит через точку A(-3;4). найдите значение коэффициента k. принадлежит ли графику этой функции точка B(2корень из 3; -2корень из 3)?

НАЙТИ количество вещества 30*10в 23 степени водорода?

Употребите в предложениях Present Perfect, выбрав пра­вильный предлог (since или for).

I've worked in the factory (for/since) 1970.

He's been abroad (for/since) five years.

 I studied French (for/since) twelve years.

 I've known her (for/since) 1982.

 I've lived here (for/since) I was a child.

 We've been in Paris (for/since) we were married.

 I've known them (for/since) years.

Поставьте глагол в скобках в форму Future Progressive or Future Simple

1. You've just missed the last train. Never mind, I (walk) ...............................        

2. I'll ring you tomorrow at six. No, don't ring at six, I (bath)....................................

3.Mother: Your face is dirty.

Child: All right, I (wash)...............

4. Will you have lunch with me on the 24th?

I'd love to, but I'm afraid I (go)...................................my exam then.

5. Why did you take his rasor? He (look) ................... for it everywhere tomorrow.

6. I hope you'll do well in the race tomorrow I (think)............................ of you.

7. I don't feel well enough to go to the station to meet him. I (meet) ........... him for you.

But how I (recognize)................................................ him?

He's small and fair, and he (wear)................................

a black and white school cap.

8.  You've left the light on.

-Oh, so I have. I (go).................................. and turn it off.

9. This time next Monday I (sit)..........................................

in a Paris caf6 reading le Figaro.

-You (not read)..................................................................

You'll be looking at all the pretty girls.

10. - Waiter, this plate is dirty.

- I'm sorry, sir, I (bring)................................................................

you another one.

ПОМОГИТЕ! К ЗАВТРАШНЕМУ ДНЮ НАДО.
кремниевая кислота H2SiO3 -> оксид SiO2
Гидрооксид железа (II) Fe(OH)2 -> оксид _____.
Сульфат алюминия Al2(SO4)3 -> гидроксиды ______ и______.
Укажите заряды ионов и степени окисления элементов в формулах.