А)
5Х - 13,5 - 3Х + 12,9 = 11
2Х - 0,6 = 11
2Х = 11,6
Х = 5,8
б)
52Х/10 + 4Х/3 + 6 = 285/15
156Х/30 + 40Х/30 + 6 = 285/15
196Х/30 = 285/15 - 6
98Х/15 = 285/15 - 90/15
98Х/15 = 195/15 = 13
98Х =13 х 15
98Х = 195
Х = 195/98 = 1 97/98
в)
9Х + 21 1/3 - 6Х + 2 2/3 = 1
3Х + 24 = 1
3Х = - 23
Х = - 23/3 = - 7 2/3
г)
4,4Х +3/7 - 1,8Х = 61/70
2,6Х = 61/70 - 3/7 = 61/70 - 30/70 = 31/70
Х = 31/70 : 26/10 = 31/70 х 10/26 = 31/7 х 1/26 = 31/182
Х = 31/182