Answer: x=2
3x−9x+7−3=−8
Step 1: Simplify both sides of the equation.
3x−9x+7−3=−8
3x+−9x+7+−3=−8
(3x+−9x)+(7+−3)=−8
−6x+4=−8
−6x+4=−8
−6x+4−4=−8−4
−6x=−12
−6x
−6
=
−12
−6
x=2
Using the binomial distribution, it is found that there is a 0.0328 = 3.28% probability that at least 2 of them choose the same quote.
<h3>What is the binomial distribution formula?</h3>
The formula is:


The parameters are:
- x is the number of successes.
- n is the number of trials.
- p is the probability of a success on a single trial.
In this problem, we have that:
- There are 6 students, hence n = 6.
- There are 20 quotes, hence the probability of each being chosen is p = 1/20 = 0.05.
The probability of one quote being chosen at least two times is given by:

In which:
P(X < 2) = P(X = 0) + P(X = 1).
Then:



Then:
P(X < 2) = P(X = 0) + P(X = 1) = 0.7351 + 0.2321 = 0.9672.

0.0328 = 3.28% probability that at least 2 of them choose the same quote.
More can be learned about the binomial distribution at brainly.com/question/24863377
Answer: C, In Step 2 the expression for y should be subsituted in the other equation.
A represents 12!
12! = 12 * 11 * 10 * 9 * ... (down to 1)