I think summer is the best season of all because it is warm, the nature is beautiful and we have great opportunities for rest. Summer is a time of holidays. We can go anywhere, spend our time near a river or a lake on fresh, green grass, swim in warm water, or climb mountains, play different games, ride a bicycle and so on.I spend my summer holidays at my granny’s. There are many things there to do. What I did most of the time - I swam in the sea and sunbathed. Sometimes I made a fire with my friends at the seaside and cooked potatoes there. It was wonderful. We told anecdotes to each other, and did everything we wanted. I also got used to walk alone in the forest.When August was coming to its end, I went on a small voyage by ship. The ship name was “Sevastopol”.But this summer wasn’t for me only sugar and honey. I have passed through the graduating exams after school and entering exams in the university. So the bigger part of my summer vacations I spent sitting with the books. Of course, it was not interesting, but I’m glad that I did it because now I’m a student of the best university in our country.
Решение: Обозначим количество пятёрок у второй подруги за (х) пятёрок, тогда первая подруга получила на 2 пятёрки меньше или: х-2 (пятёрок) третья подруга получила на 2 пятёрки больше чем вторая или: х+2 (пятёрок) четвёртая подруга получила пятёрок на 2 пятёрки больше чем третья или: (х+2)+2=х+4 (пятёрки) А так как подруги вместе получили 40 пятёрок составим уравнение: (х-2)+х+(х+2)+(х+4)=40 х-2+х+х+2+х+4=40 4х+4=40 4х=40-4 4х=36 х=36 : 4 х=9 (пятёрок получила вторая подруга) Отсюда: у первой подруги: (9-2)=7 (пятёрок) у третье подруги: (9+2)=11 (пятёрок) у четвёртой подруги:(9+4)=13 (пятёрок)
ответ: пятерок у подруг: 1-ой-7; 2-ой-9; 3-й-11; 4-й-13 (пятёрок)
