Answer:
m =

Explanation:
2m + 1 = -3m - 1 (Given)
2m + 1 + 1 = -3m - 1 + 1 (Addition Property of Equality)
2m + 2 = -3m (Simplify)
2m - 2m + 2 = -3m - 2m (Subtraction Property of Equality)
2 = -5m (Simplify)
(Division Property of Equality)
= m (Simplify)
m =
(Symmetric Property of Equality)