I would say that you could. In theory, all contractions are less formal than the full length version of words, but the word doesn't is used so commonly that it really wouldn't matter to anyone if you used it.
it is not unusual to say "in fact," in a formal lettter
When composing a formal letter, it is important to follow these guidelines: use a professional tone, include the recipient's address, date, and a formal greeting, organize the letter with clear paragraphs, use a formal closing and signature, and proofread for errors before sending.
When writing a letter to a professor, use a formal format that includes your contact information, the professor's contact information, a formal greeting, a clear and concise introduction, the main body of the letter, a polite closing, and your signature.
yes it is formal because it doesnt use slang and too much puncuation the lonely planet guide does use puncuation but not too much unlike the email
One would use formal language in a business letter because it is a formal means of communication. When writing a business letter, one wants the tone to be professional. Formal language can help the writer to achieve this.
i would use a semi colon ; just because that is More formal.
use formal and semi-formal language
respected
The proper etiquette for signing a formal letter is to use a formal closing such as "Sincerely" or "Yours truly," followed by your full name and title if applicable.
it doesnt.
Well, you use thank you either if it's a formal letter (and in any part of it) or not while you normally use best regards at the end of a formal letter
a letter to your congressional representative. *apex homie*