1. Решение уравнений:
- X + 19 = 42
X = 42 - 19
X = 23 - 54 + X = 82
X = 82 - 54
X = 28 - 17 - Y = 9
Y = 17 - 9
Y = 8 - C - 28 = 70
C = 70 + 28
C = 98 - Y * 42 = 84
Y = 84 / 42
Y = 2 - 76 : X = 2
X = 76 / 2
X = 38
Ответ: X = 23, X = 28, Y = 8, C = 98, Y = 2, X = 38