The answer is HJ i took the test and got it right :)
Answer A:the number of students who watch 6 to 9 hours of TV
Step-by-step explanation:
Just took the test.
The axis of symmetry of a parabola is a line that divides it into two similar halves and this axis always goes through the vertex.
To find the equation of the line that represents the symmetry of the curve, suppose a parabola of the form 
Then, deriving y with respect to x we have:

By matching dy / dx to 0 we have and by clearing x we have:

This equation allows us to find the axis of symmetry for any quadratic function
Then for the first function of the image.
The axis of symmetry is:


For the second function of the image:


For the third function the axis of symmetry is observed with the naked eye, is the line of equation:

Answer:
9 2/7
Step-by-step explanation:
4 1/3=13/3
2 1/7=15/7
13/3*15/7= 195/21
=9 6/21
=9 2/7
9x^2 + 6x = 1
Factor out 3x
3x (3x +2)=1
Use the zero product property
3x=1
3x+2 = 1
X= +1/3 and -1/3