First, we are going to rewrite it as a parabola equation.
Rewrite.

Divide by 8.

Factor out coefficient.

Then, we are going to convert x into square form.

Convert the whole expression into square form.

Simplify.

Subtract 6 from both sides.

Divide by coefficient.

Rewrite in standard form.
The radius of the circle will be -2. Also, no matter what the sign says, the radius has to always be positive.
Have a nice day! :)
Answer:
12
Step-by-step explanation:
Let the number = x
7x + 1 = 5x + 25 Subtract 5x from both sides.
7x - 5x + 1 = 5x - 5x + 25 Combine
2x + 1 = 25 Subtract 1 from both sides.
2x + 1 - 1 = 25-1 Combine
2x = 24 Divide by 2
2x/2 = 24/2
x = 12
Answer:
3
Step-by-step explanation:
ANSWER

EXPLANATION
Since the directrix is

the axis of symmetry of the parabola is parallel to the y-axis.
Again, the focus being,

also means that the parabola will open upwards.
The equation of parabola with such properties is given by,

where

is the vertex of the parabola.
The directrix and the axis of symmetry of the parabola will intersect at

The vertex is the midpoint of the focus and the point of intersection of the axis of the parabola and the directrix.
This implies that,

and

The equation of the parabola now becomes,


Thus, the distance between the vertex and the directrix.
This means that,

Since the parabola opens up, we choose

Our equation now becomes,

This simplifies to

or

This is the same as,

The correct answer is D .