First you must have the quadratic equal to zero. In order to do this you must subtract 7 to both sides
x^2 + 20x + (100 - 7) = 7 - 7
x^2 + 20x + 93 = 0
Now you must find two numbers who's sum equals 20 and their multiplication equal 93
Are there any? NO!
This means that you have to use the formula:

In this case:
a = 1
b = 20
c = 93



^^^We must simplify √28
√28 = 2√7
so...

simplify further:

-10 + √7
or
-10 - √7
***plus/minus = ±
Hope this helped!
~Just a girl in love with Shawn Mendes
The answer would most likely be C
Answer: Random sampling
Step-by-step explanation:
- A random sampling technique is a method of sampling in which each member for the sample is chosen randomly from the population.
- Systematic sampling : It is a kind of random sampling in which the members get selected after a fixed interval but a random starting point.
- Convenience sampling : It is a kind of random sampling in which the members get selected on the basis of researchers convenience.
- Stratified sampling : It is a kind of random sampling in which the entire population is divided into a finite number of strata , the researcher select members for sample from each strata.
- Cluster sampling : It is a kind of random sampling in which the entire population is divided into clusters. Then a random sample of cluster is drawn by researcher.
In the given situation , 784 adults are selected after their telephone numbers were randomly generated by a computer.
Therefore , the type of sampling used here is : random sampling
Answer: The answer is B
Step-by-step explanation: Can I get brainliest