Если к данному числу приписать справа цифру 9 и к полученному числу прибавить удвоенное данное число , то сумма будет равна 633.Найдите данное число.

В правильной четырёхугольной пирамиде апофема равна 5 см. Двугранный угол при основании равен 45 градусов. Найти площадь полной поверхности пирамиды.

а) Петя решил 4 примера, что составило четверть домашнего
задания. Сколько примеров задали Пете?
б) В ящик сеялки было засыпано 250 кг зерна. После 2 часов работы
количество зерна уменьшилось на 20%. Сколько килограммов
зерна осталось в ящике сеялки?
в) Одна тетрадь стоит 3 р. 60 коп. Сколько можно купить тетрадей на 15 рублей

Из города А в город В вышел поезд со скоростью 50 км/ч. Через 3 ч из
города В ему навстречу вышел поезд со скоростью 60 км/ч. Через
сколько часов после выхода второго поезда они встретились, если
расстояние между городами 480 км?

Перевод не нужен! Проверьте правильность написания

3. I guess many TV sets stops people from arguing over which channel to choose from, doesn’t it?

Nowadays technology develops very fast. A lot of families can afford to have more than one TV sets at home.

On the one hand many TV sets allow each member of family to watch channel he want. While children are watching cartoons, father can watch football and mother can watch serial. Moreover there are no quarrels about choosing channels between members of family.

On the other hand people spend a lot of time watching TV. And if they have many TV sets they spend still more time near them. And what’s more children less communicate with parents. There is no unity in the family.

To sum up families should decide themselves to buy some more TV sets or not.

Personally I don’t watch TV at all. I use my computer to know news and watch films. I think TV set occupies much place.

4. Are all sports healthy?

Sport is very important in our life. It’s popular among young and old people. Some people say sport is really useful.

On the one hand sport helps people to keep fit and healthy. People going in for sport don’t often get ill. Moreover sport helps people to be in the good mood, gives spirit and energy and saves from stress and depression.

On the other hand some kinds of sport like diving, snowboarding, rock climbing and others are dangerous, because you may get injury or even die. And what’s more some people think sport distracts from intellectual development.

To sum up people should decide themselves to go in for sport or not.

Personally I think sport is very important for me. I try to do exercises every day. I think sport helps me to look fit.

решить уравнение sin3x*sin2x=1