Final answer:
The main purpose of Brandt's letter is to inform the audience about a specific topic and provide relevant information. Brandt plans on accomplishing this by explaining the subject matter clearly and concisely.
Step-by-step explanation:
The main purpose of the letter from Brandt is to inform the audience about a specific topic. Brandt plans on accomplishing this through providing relevant information and explaining the subject matter in a clear and concise manner. The author wants the audience to understand the topic and potentially take action based on the information provided in the letter.