(a) Using the completing the square method, we need to write into the form of where , so
Expand to find the value of c
Notice that we get back the first two terms, the and the .We need to get rid of the last term of '9' as the term was not in the original form. The final form will look like
Hence,
(b)
(c) , square root both sides plus and minus of 2 Hence
(x+1)•(5x-2) hope this helps
Answer:

Step-by-step explanation:
Let's call y the number of patients treated each week
Let's call x the week number.
If the reduction in the number of patients each week is linear then the equation that models this situation will have the following form:

Where m is the slope of the equation and b is the intercept with the x-axis.
If we know two points on the line then we can find the values of m and b.
We know that During week 5 of flu season, the clinic saw 90 patients, then we have the point:
(5, 90)
We know that In week 10 of flu season, the clinic saw 60 patients, then we have the point:
(10, 60).
Then we can find m and b using the followings formulas:
and 
In this case:
and 
Then:


And


Finally the function that shows the number of patients seen each week at the clinic is:

Answer: Around 96 people would prefer creamy peanut butter.
Step-by-step explanation:
In the survey was found that 4 out of 5 preferred creamy over chunky peanut butter.
Then the relative frequency is:
4/5 = 0.8 prefer creamy peanut butter.
And we can assume that:
1/5 = 0.2 prefer chunky peanut butter.
We also could multiply these numbers by 100% to obtain the percentage forms:
0.8*100% = 80%
0.2*100% = 20%
Now, if there are 120 people in the grocery store, we can expect that the 80% will prefer creamy peanut butter.
Then we can expect that the number of people that prefers creamy peanut butter is:
N = (80%/100%)*120 = 0.8*120 = 96
Around 96 people would prefer creamy peanut butter.