Пожалуйста. чем отличаются прокариоты от эукариотов.

Килограмм шоколадных конфет стоит а рублей, килограмм карамели стоит b рублей.
а) Что было куплено,если стоимость покупки (В рублях) равна а + b? 3b? 2а? 2а + b? 
б) Каковы смысл выражений a-b?

3x^2-x-2≥0 Помогите решить неравенство

42 Use the words from Ex. 41 to join the ideas in these sentences.

1. His car is very fast. It is very expensive.

2. We were tired. We had been travelling for a week.

3. The weather was awful. It was pouring with rain. It was cold.

4. We left home early. We arrived late.

5. I was late for school. The traffic was really bad.

6. I never get a taxi. It’s too expensive.

7. The weather was bad. We still went out for a walk.

8. They have a car. They rarely use it

Вот 41е упражнение, но оно мне не нужно:

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41 Put the words and phrases into three categories in the table. Use your Workbook.

besides, although, in addition (to), because, also, however, despite, as well as, since, as, but, and, what is more, in spite of, due tor too, whereas, on the other hand

Addition | Contrast | Cause / Reason

Допоможіть розвязати  текстову задачу "Від пристані униз річкою відправили пліт,що рухався зі швидкістю 4 км/год. Через 3 год слідом за ним вийшов човен, власна швидкість якого 9км/год. На якій відстані від пристані човен наздожене пліт?