Решение:
- \( 6a + 8a = (6 + 8)a = 14a \)
- \( 28c - 15c = (28 - 15)c = 13c \)
- \( m + 29m = (1 + 29)m = 30m \)
- \( 98p - p = (98 - 1)p = 97p \)
- \( 4x + 13x + 15x = (4 + 13 + 15)x = 32x \)
- \( 67z - 18z + 37 = (67 - 18)z + 37 = 49z + 37 \)
Ответ: 1) 14a; 2) 13c; 3) 30m; 4) 97p; 5) 32x; 6) 49z + 37.