Exact form:
5/7
Decimal form:
0.71428571...
Answer:
Option b which is 
Step-by-step explanation:
We have been given the discriminant 12
We have to choose the equation which will satisfy the given discriminant.
We will consider all the given equation one by one
First we will take option a which is 
Discriminant from the equation we will find by the formula

Here, a=-1,b=8 and c=2 on substituting the values we will get

Hence, option a is incorrect.
Now, we will consider option b which is 
Here, a=2,b=6 and c=3 on substituting the values we get

Hence, option b is correct
Therefore, option b is the required answer.

now, a line perpendicular to that one, will have a "negative reciprocal" slope, thus
The question given is incomplete, I googled and got the complete question as below:
You are a waterman daily plying the waters of Chesapeake Bay for blue crabs (Callinectes sapidus), the best-tasting crustacean in the world. Crab populations and commercial catch rates are highly variable, but the fishery is under constant pressure from over-fishing, habitat destruction, and pollution. These days, you tend to pull crab pots containing an average of 2.4 crabs per pot. Given that you are economically challenged as most commercial fishermen are, and have an expensive boat to pay off, you’re always interested in projecting your income for the day. At the end of one day, you calculate that you’ll need 7 legal-sized crabs in your last pot in order to break even for the day. Use these data to address the following questions. Show your work.
a. What is the probability that your last pot will have the necessary 7 crabs?
b. What is the probability that your last pot will be empty?
Answer:
a. Probability = 0.0083
b. Probability = 0.0907
Step-by-step explanation:
This is Poisson distribution with parameter λ=2.4
a)
The probability that your last pot will have the necessary 7 crabs is calculated below:
P(X=7)= {e-2.4*2.47/7!} = 0.0083
b)
The probability that your last pot will be empty is calculated as:
P(X=0)= {e-2.4*2.40/0!} = 0.0907