\( \frac{10c}{10} + \frac{2(c+2)}{10} - \frac{3c-1}{10} \ge \frac{80}{10} \)
\( 10c + 2(c+2) - (3c-1) \ge 80 \)
\( 10c + 2c + 4 - 3c + 1 \ge 80 \)
\( (10c + 2c - 3c) + (4 + 1) \ge 80 \)
\( 9c + 5 \ge 80 \)
\( 9c \ge 80 - 5 \)
\( 9c \ge 75 \)
\( c \ge \frac{75}{9} \)
\( c \ge \frac{25}{3} \)
\( c \ge 8\frac{1}{3} \)
Ответ: [8\(\frac{1}{3}\); +∞)