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.
The functions shows in the data table is an exponential function.
It is equal when you round it off.
Answer:

Step-by-step explanation:
For #2, remember that
, so
Also, (a+b)(a-b), where a and b are any numbers, (a+b)(a-b)=
. Now, to simplify, or radicalize, a number with surds in the denominator, you have to multiply the denominator by its conjugate. If there is a complex number
, where a and b are any numbers, the conjugate is always
. Lets apply these rules. The conjugate of 4+6i is 4-6i, so do this:

Our answer is (28-3i)/(26)!