8. As a motivational speaker, Bree speaks at school assemblies, charging a school district for her travel costs and a fixed amount per assembly. Bree used the equation C = 50a + 1,500 to determine the charge of C dollars to speak at a assemblies in the Escambia City School District. Bree charged the district $4,250 to speak at school assemblies. How many assemblies did Bree speak at in this district?