It is always important to go through the given problem first to get a concept of the requiremement. Then all the information's available from the question has to be noted down in such a manner that there would be no need to look at the question while solving.
Total number of students wearing jeans = 10
Total number of students wearing shorts = 9
Total number of students wearing capris = 2
Then the total number of students surveyed by Mrs Lane = (10 + 9 + 2)
= 21
Now percentage of students wearing shorts = (9/21) * 100
= (3/7) * 100
= 300/7
= 42.85 percent
So a total percentage of 42.85% of the students were wearing shorts.
It would appear your original equation is in Y=MX+b form, where M=2
y=0
................your welcome
Answer: Option D

Step-by-step explanation:
For a quadratic function of the form

The x coordinate of the vertice is:

In this case the function is:

So

The x coordinate of the vertice is:

The y coordinate of the vertice is:

The vertice is: (-3, -11)
The form e vertice for a quadratic equation is:

Where
the x coordinate of the vertice is h and the y coordinate of the vertice is k.
Then h=-3 and k =-11
Finally the equation
in vertex form is:

If 1 is 65 then:
2=180-65=115
3=65
4=115
5=115
6=65
7=115
8=65