The school year always starts on September 1. Though uniforms are no longer enforced in most of the schools, children, especially first-graders, wear white shirts or blouses. Primary school students study five or six days a week and usually have four 40-45 minute classes a day. The intervals between classes vary from 5 to 25 minutes. Each student has a special record book (dnevnik) for writing down the schedule and home assignment every day of the week. The teacher uses the dnevnik to record the student's grades and remarks about his or her behavior. It is considered to be an effective method of the teacher's communication with parents. The academic year is organized on a quarterly basis, with four vacations (a week in early November, two weeks for the New Year and Christmas, a week at the end of March, and three months in the summer). Students are graded for every subject at the end of each quarter and the academic year. The grading is numerical: five, excellent; four, good; three, fair; and two, poor (failure).
I 57 л ? л ?
II 84 л ? л на 9 банок >
I - II 84 - 57 = 27 л 27 : 9 = 3 л
1) 84 - 57 = 27 л больше яблочного
2) 27 : 9 = 3 л объем 1 банки
3) 57 : 3 = 19 банок томатного сока
4) 84 : 3 = 28 банок яблочного сока
5) 28 - 19 = 9 банок разница
(240 - 2*х) : 30 = 7
240 - 2*х = 7 * 30
240 - 2*х = 210
2*х = 240 - 210
2*х = 30
х = 30 : 2
х = 15
(240 - 2 * 15) : 30 = 7
(240 - 30) : 30) = 7
210 : 30 = 7
7 = 7
ответ: х = 15
method of the teacher's communication with parents. The academic year is organized on a quarterly basis, with four vacations (a week in early November, two weeks for the New Year and Christmas, a week at the end of March, and three months in the summer). Students are graded for every subject at the end of each quarter and the academic year. The grading is numerical: five, excellent; four, good; three, fair; and two, poor (failure).