Answer:
$122.88
Step-by-step explanation:
the phone decreases by 20% each year , that is
(100 - 20)% = 80% =
= 0.8
the phone reduces by a factor of 0.8 each year , then after 4 years
value = $300 ×
= $122.88
Answer:
x=-4
Step-by-step explanation:
-18=2+5x
Subtract 2 from both sides
-20=5x
-4=x
Answer: Option D.
Step-by-step explanation:
You can calculate the surface area of this right prism by adding the area of its faces.
You can observe that the faces of the right prism are: Three different rectangles and two equal triangles.
The formula for calculate the area of a rectangle is:

Where "l" is the lenght and "w" is the width.
The formula for calculate the area of a triangle is:

Where "b" is the base and "h" is the height.
You can observe that the hypotenuse of the each triangle is the width of one of the larger rectangle, then , you can find its value with the Pythagorean Theorem:

Where "a" is the hypotenuse and "b" and "c" are the legs of the triangle.
Then, this is:

Therefore, you can add the areas of the faces to find the surface area of the right prism (Since the triangles are equal, you can multiply the area of one of them by 2). This is:

The after 9/4 seconds the football is at its highest point which is 81 feet if Lillian kicks a football. Its height in feet is given by h(t)= -16t²+72t
<h3>What is a parabola?</h3>
It is defined as the graph of a quadratic function that has something bowl-shaped.

Making perfect square:
![\rm h(t)= -[(4t)^2-72t+9^2 -9^2]](https://tex.z-dn.net/?f=%5Crm%20%20h%28t%29%3D%20-%5B%284t%29%5E2-72t%2B9%5E2%20-9%5E2%5D)
![\rm h(t)= -[(4t-9)^2 -81]](https://tex.z-dn.net/?f=%5Crm%20%20h%28t%29%3D%20-%5B%284t-9%29%5E2%20-81%5D)

The highest point will be when term (4t-9)² becomes zero
So the highest point = 81 feet, and it takes:
t = 9/4 seconds
Thus, the after 9/4 seconds the football is at its highest point which is 81 feet if Lillian kicks a football. Its height in feet is given by h(t)= -16t²+72t
Learn more about the parabola here:
brainly.com/question/8708520
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