Answer:
Discriminant= b²-4ac
a = 9 b = -3 and c = -2
Discriminant = (-3)² - 4(9)(-2)
= 9+72
Discriminant = 81
Ans = 81
The first one and it's written as a(-1)(n-1). The parenthesis around the n-2 are important
To the nearest whole percent the margin error for this poll would be <span>38% ⁺/₋ 14%. If you want me to explain feel free to ask! </span>
Answer:
8.81% probability that the student answers exactly 4 questions correctly
Step-by-step explanation:
For each question, there are only two possible outcomes. Either he answers it correctly, or he does not. The probability of answering a question correctly is independent of other questions. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

In which
is the number of different combinations of x objects from a set of n elements, given by the following formula.

And p is the probability of X happening.
A multiple choice exam has ten questions.
This means that 
The probability of answering any question correctly is 0.20.
This means that 
What is the probability that the student answers exactly 4 questions correctly
This is P(X = 4).


8.81% probability that the student answers exactly 4 questions correctly
2 to the fourth power is technically
2 × 2 × 2 × 2 = 16
4 to the second power is
4 × 4 = 16
The answer is 256