23 - 3(b + 1) + 5(6b - 7) - 7(3b - 1) = 0
23 - 3b - 3 + 30b - 35 - 21b + 7 = 0
6b - 8 = 0
6b = 8
b = 8/6 = 4/3 = 1 1/3
ответ: 1 1/3
23 - 3(b + 1) + 5(6b - 7) - 7(3b - 1) = 0
23 - 3b - 3 + 30b - 35 - 21b + 7 = 0
6b - 8 = 0
6b = 8
b = 8/6 = 4/3 = 1 1/3
ответ: 1 1/3