Answer:
50 ≤ e ≤ 100
Step-by-step explanation:
For one photography session, Dexter earns no less than 50. This means that the least he can gain in a session is $50.
For one photography session, Dexter earns no more than 100. This means that the most he can gain in a session is $100.
So:

He can earn 50 and he can earn 100, so the equal sign is part of the interval.