Answer:
The probability is 
Step-by-step explanation:
If she has n distinct password candidates and only one of which will successfully log her into a secure system, the probability that her first first successful login will be on her k-th try is:
If k=1

Because, in her first try she has n possibles options and just one give her a successful login.
If k=2

Because, in her first try she has n possibles options and n-1 that are not correct, then, she has n-1 possibles options and 1 of that give her a successful login.
If k=3

Because, in her first try she has n possibles options and n-1 that are not correct, then, she has n-1 possibles options and n-2 that are not correct and after that, she has n-2 possibles options and 1 give her a successful login.
Finally, no matter what is the value of k, the probability that her first successful login will be (exactly) on her k-th try is 1/n
AB²=5²+5²+5²=25+25+25=75
AB=5√3≈8.7
Answer:AB≈8.7
The answer would be one of the following in the photo below....if not do you have a picture you could show me of the possible answers?
1.) Distribute 4 to (3x) & (8):

,

2.) Rewrite the expression:

3.) Combine like terms:

4.) Rewrite the final expression:
Final Answer: <span>

Hope this helps!!
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