$[L:K]$ is prime [closed]

Question

If $[L:K]$ is prime, show that $L$ is a simple extension of $K$.

Please don't post in the imperative mode; if you have a question on this problem, it's best to say what your question is or where you are stuck and what you have succeeded in doing. Thank you.
@user8465: It doesn't take much English to pose a question instead of simply issuing an order. What you posted is an order, not a question. I also have to wonder: if you English is so poor that are unable to take this problem and pose it as a question, will you be able to understand the answers you get?
@user8465: Your Spanish seems pretty good; your attitude, alas, doesn't.
@Akhil: I have no objection to closing the question, but the reason for closing doesn't make much sense to me. I don't think anyone has any trouble seeing what the question is here, and it's not "ambiguous, vague, overly broad or rhetorical". It's true that the OP did not phrase it in the form of a question, but this is not Jeopardy -- that's not really the reason for closing, is it?
@Pete: There was an abusive comment left by the OP (directed at me) which has been deleted. This is no doubt large part of the reason behind the closing and the fact that the OP is suspended for a time.

Arturo Magidin · Answer 1 · 2011-04-04 00:09:08Z

up vote 13 down vote

Hint: If $a\in L$, what are the possible values of $[K(a):K]$?

answered Apr 4 '11 at 0:09

Arturo Magidin
158k14250501

closed as too localized by Akhil Mathew Apr 4 '11 at 3:09