The document proposes a framework for dynamic network slicing and resource allocation in mobile edge computing systems to maximize an operator's revenue while considering traffic variations. It develops the Dynamic Network Slicing and Resource Allocation (DNSRA) algorithm that jointly optimizes slice request admission and resource allocation without any prior knowledge of traffic. The DNSRA tackles the coupled optimization problem through variable decoupling and develops closed-form solutions for user association and CPU allocation along with approximation methods for power allocation and subcarrier assignment. A heuristic algorithm is also developed for dynamic slice request admission. Simulation results show the DNSRA can balance revenue and delay while increasing operator revenue over existing schemes.