The vertex of the parabola is between the shortest line connecting its focus and directrix, so between (0, -4) and y = 4 is the point (0, 0), which is the vertex of the parabola. Also, this parabola faces downward.
The general formula for a parabola that faces downward is y = -4cx^2, where c is the distance from the vertex to either to focus or the parabola. Since c = 4, the equation is y = -16x^2, which is choice A.
Given, y varies directly as x
So,

Where c is a constant
When y equals 5 when x is 8
So,

So, the relation between y and x

now , when x = 9
Substitute with x to find y

So, the answer is option 2. y = 45/8
Answer: 93
Step-by-step explanation:
Answer:
=
Step-by-step explanation:
Substitute 3 in for m and solve
4m - 1 = 4(3) - 1 = 11
5m - 4 = 5(3) - 4 = 11
Answer:
Step-by-step explanation:
-4=2x+16
-16. -16
-20=2x
20/2=2x/2
10=x