Problem 2 (25 points) Consider the following excerpt from a database schema about an electronics seller. Product(company, model, type) Phone(model, cpu, ram, cellular_network, price) Headset(model, color, connection_method, price) Charger(model, color, plug_type, price) Give an expression in relational algebra for each of the following queries: 1. Which Phone models support 5g ? [5 points] 2. Which companies make phones with at least 8GB of RAM? [5 points] 3. Which manufacturers make phones but not headsets? [ 5 points] 4. What RAM size is present in at least two distinct phone models? [5 points] 5. Which company makes the most expensive charger? [ 5 points]