4. 67 + x = 2400 : 8 y - 143 = 18 * 3 c * 19 = 2000 - 100

Решим уравнения: 1. (67 + x = 2400 : 8) (67 + x = 300) (x = 300 - 67) (x = 233) 2. (y - 143 = 18 \cdot 3) (y - 143 = 54) (y = 54 + 143) (y = 197) 3. (c \cdot 19 = 2000 - 100) (c \cdot 19 = 1900) (c = 1900 : 19) (c = 100)