**Решение:**
1) \[(x - 50,6) + 2,15 = 42,9\]
\[x - 50,6 = 42,9 - 2,15\]
\[x - 50,6 = 40,75\]
\[x = 40,75 + 50,6\]
\[x = 91,35\]
2) \[31,28 - (m + 4,2) = 15,093\]
\[m + 4,2 = 31,28 - 15,093\]
\[m + 4,2 = 16,187\]
\[m = 16,187 - 4,2\]
\[m = 11,987\]
**Ответы:**
1) x = 91,35
2) m = 11,987