Из одного села одновремено в одном направлении отправились пешеход и велосипедист пешеход двигался со скоростью 3км ч а велосепедист 12кмч какое растояние будет между ними через 3 ч

3*3=9 столько км пешеход,
3*12=36 столько км проехал велосепедист
36-9=27 столько км будет между ними через 3 часа

 I have a separate room of my own, which is nice. However, I would like to make some changes there. My current room is of light green colour but I’d like it to be orange. I like warm and welcoming colours. My mum promised to change the wallpapers this year, so I hope to have my dream room soon. Another thing I’d change is the shape and size of my wardrobe. I have a huge rectangular wardrobe of dark hazel colour. Instead, I’d like to have a smaller one with oval top and city landscapes on it. I’d like to have a bunk bed in my room. At the moment I’m sleeping on a huge sofa, which occupies half of the room’s space, whereas bunk beds are more comfortable and compact. Sometimes my friend Polina visits me and wants to stay overnight. With a bunk bed it would be much easier, as she could sleep on its top bunk. In the right corner I have a small study with a desk, a chair, a computer, a lamp and some book shelves. I wouldn’t like to change anything there as it’s a very cozy corner. I do my home-works and additional projects there. Speaking of a computer, I dream of a cute pink laptop. Mine is an old desktop computer which is often slow to react. So my dream room should contain a new laptop. My parents don’t want me to keep any pets in the flat. But in my dreams I wish I could keep a small turtle and a hamster in my room. Also, a large fish-tank with colourful fishes would be nice. When I have such a perfect room, I’ll invite friends over more often.

Надо решить систему из двух уравнений:
{-R1*cos70+R2*cos45=0          {R1*cos70-R2*cos45 = 0  (меняем знаки)
{R1*cos20+R2*cos45-G=0       {R1*cos20+R2*cos45 = G
                                                   
                                                  = R1*cos70 +  R1*cos20 = G   (сумма)
                                                    R1*(cos70 + cos20) = G. 
Отсюда R1 = G / (cos70 + cos20).
Тут есть 2 варианта решения - подставить значение G. найти табличные значения косинусов и получить результат.
По второму варианту можно искать сумму косинусов двух углов. Но и в таком случае не обойтись без таблицы (калькулятора).

R1 = 350 / ( 0.34202 + 0.939693) = 350 / 1.281713 =  273.0721.