Answer:
D
Step-by-step explanation:
The area and the radius of a sphere are related by the formula:
A=4πr^2
Let’s say this is A1 and r1
Now the radius is tripled. This means r2 = 3r1
The new area thus becomes: A = 4 * (3r)^2 * π = 36πr^2
Comparing A1 and A2 , we can see that A2 = 9A1
Answer: The ball hits the ground at 5 s
Step-by-step explanation:
The question seems incomplete and there is not enough data. However, we can work with the following function to understand this problem:
(1)
Where
models the height of the ball in meters and
the time.
Now, let's find the time
when the ball Sara kicked hits the ground (this is when
):
(2)
Rearranging the equation:
(3)
Dividing both sides of the equation by
:
(4)
This quadratic equation can be written in the form
, and can be solved with the following formula:
(5)
Where:
Substituting the known values:
(6)
Solving we have the following result:
This means the ball hit the ground 5 seconds after it was kicked by Sara.
Answer:
s = - 1 ± 
Step-by-step explanation:
Given
s² + 2s - 6 = 0 ( add 6 to both sides )
s² + 2s = 6
To complete the square
add ( half the coefficient of the s- term )² to both sides
s² + 2(1)s + 1 = 6 + 1
(s + 1)² = 7 ( take the square root of both sides )
s + 1 = ±
( subtract 1 from both sides )
s = - 1 ± 
Thus
s = - 1 -
, s = - 1 + 
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Answer:
He washed 4 cars.
Step-by-step explanation:
1. The variable that was unknown x amount of cars washed.
2.The equation I used was 110-50=15x
3. To solve this you subtract the 50$ from 110$ you get sixty dollars you do that to take out what he earned for his allowance. Then your equation is 60=15x so you divide each side by 15 and when you do that x=4