Answer:
there are no real solutions
Step-by-step explanation:

there is a rule that says

so we have

and we have the definition

so we have

and using the quadratic formula we get that
there are no real solutions
Answer:
c. Zhen spends 6 1/2 hours working per audiobook.
Step-by-step explanation:
The table below gives some completed audio lengths and the amount of time Zhen spends on the audiobook.

We observe that from the table, in 6.5 hours, Zhen completes 1 audiobook.
In fact, across the table:

Therefore, in this situation, 6.5 hours mean that Zhen spends 6.5 hours working per audiobook.
The correct option is C.
Answer:
(a) Rule: Multiply the input (x) by 2 and add 5 to the result of the product
(b) 
Step-by-step explanation:
Given
The attached table
Solving (a): The rule of the table in words
First, we calculate the slope (m)

Using:


So, we have:



The equation is calculated using:

Using:

We have:


Make y the subject


Hence, the rule is:
Multiply the input (x) by 2 and add 5 to the result of the product
(b): The rule, in algebra
As solved in (a), the rule is:

Answer:
The mean of the remaining 3 boys is 51.
Step-by-step explanation:
The mean mark of the entire group (
), dimensionless, is:
(Eq. 1)
(
)
(Eq. 1b)
Where
is the mark of the i-th boy, dimensionless.
In addition, we know the following mean marks from statement:
(Eq. 2)
(
)
(Eq. 2b)
(Eq. 3)
Where:
- Mean mark of the first 7 boys, dimensionless.
- Mean mark of the remaining 3 boys, dimensionless.
By applying sum properties in (Eq. 1b) and using (Eq. 2b) and (Eq. 3), we obtain the mean of the remaining 3 boys:
![\frac{1}{10}\cdot [\Sigma_{i = 1}^{7}x_{i}+\Sigma_{i=8}^{10}x_{i}] = 58](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B10%7D%5Ccdot%20%5B%5CSigma_%7Bi%20%3D%201%7D%5E%7B7%7Dx_%7Bi%7D%2B%5CSigma_%7Bi%3D8%7D%5E%7B10%7Dx_%7Bi%7D%5D%20%3D%2058)
![\frac{1}{10}\cdot [7\cdot (61)+3\cdot p_{3}] = 58](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B10%7D%5Ccdot%20%5B7%5Ccdot%20%2861%29%2B3%5Ccdot%20p_%7B3%7D%5D%20%3D%2058)




The mean of the remaining 3 boys is 51.
1372/3n I hope this helped :)