4. Реши уравнения: 67 + x = 240; y − 143 = 16; c · 19 = 209.

1) \(67 + x = 240\)

\(x = 240 - 67 = 173\).

2) \(y - 143 = 16\)

\(y = 16 + 143 = 159\).

3) \(c \cdot 19 = 209\)

\(c = 209 : 19 = 11\).

Ответ: x = 173, y = 159, c = 11.