Answer:
She should be expected to have 2.11 aces.
Step-by-step explanation:
I suppose there was a small typing mistake. It should be: On average she gets an ace of 8.44% of her serves.
Then
For each serve, there are only two possible outcomes. Either there is an ace, or there is not. The probability of there being an ace in a serve is independent of other serves. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
Probability of exactly x sucesses on n repeated trials, with p probability.
The expected value of the binomial distribution is:

She gets an ace of 8.44% of her serves.
This means that 
She attemps 25 serves:
This means that 
How many aces would you expect her to have

She should be expected to have 2.11 aces.
The first one because if you add all the positives you get 4 and then if you add all the negatives you get 7 so then you do 4+(-7)= -3
X value is 20 concert tickets y value is 10 dollars
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Answer:</u></h2>
n²-25
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Explanation:</u></h2>
Expand the polynomial using the FOIL method. (A handy way to remember how to multiply two binomials. It stands for "First, Outer, Inner, Last")