Задание 4.
1) 4778 : 114 = 42 ;
2) 42 * 114 = 4778 ;
3) х : 42 = 114
х = 114 * 42
х = 4778
4) х : 114 = 42
х = 42 * 114
х = 4778
5) 42 * х = 4778
42х = 4778
х = 4778 / 42
х = 114
6) 114 * х = 4778
114х = 4778
х = 4778 / 114
х = 42
Задание 7.
( х + х + 2 + х + 4 ) * 311 = 40199
( 3х + 6 ) * 311 = 40199
3х + 6 = 40199 / 311
3х + 6 = 129
3х = 129 - 6
3х = 123
х = 123/3
х = 41
41 + 2 = 43
41 + 4 = 45
Проверка :
( 41 + 43 + 45 ) * 311 = 40119