Answer:
x = 12
Step-by-step explanation:
Step 1: Write quadratic
x² - 24x + 144 = 0
Step 2: Factor
(x - 12)(x - 12) = 0
Step 3: Find roots
x - 12 = 0
x = 12
Just divide 16 by 100: 16/100=0.16, So, the answer is C. 0.16
The answer is B: 6 cm. You can use guess-and-check method, and plug the possible different answers into the equation x(x+6)=72, x stands for the width.
The sketch of the parabola is attached below
We have the focus

The point

The directrix, c at

The steps to find the equation of the parabola are as follows
Step 1
Find the distance between the focus and the point P using Pythagoras. We have two coordinates;

and

.
We need the vertical and horizontal distances to find the hypotenuse (the diagram is shown in the second diagram).
The distance between the focus and point P is given by

Step 2
Find the distance between the point P to the directrix

. It is a vertical distance between y and c, expressed as

Step 3
The equation of parabola is then given as

=


⇒ substituting a, b and c


⇒Rearranging and making

the subject gives