A) The elevation of Tammy's house is 42.35 feet.
Answer:

Step-by-step explanation:
Linear function:
A linear function has the following format:

In which m is the slope and b is the q-intercept.
One week you charged $4 per guest and averaged 80 guests per night. The next week you charged $10 per guest and averaged 44 guests per night.
This means that we have these following points: (4,80), (10,44).
Finding the slope:
With a pair of points, the slope is given by the change in q divided by the change in p.
Change in q: 44 - 80 = -36
Change in p: 10 - 4 = 6
Slope: 
So

Finding b:
We replace one of the points. Replacing (4,80).



So

Answer: The quadrilateral HIJK is a parallelogram.
Explanation:
It is given that the coordinates of the vertices for the figure HIJK are H(0, 5), I(3, 3), J(4, –1), and K(1, 1).
The parallelogram diagonal theorem states that the quadrilateral is a parallelogram if both diagonal bisects each other.
If HIJK is a quadrilateral, then HJ and IK are the diagonals of HIJK.
First we find the midpoint of HJ.


Now, find the midpoint of IK.


The midpoint of both diagonal are same. It means the diagonals of HIJK bisects each other.
By parallelogram diagonal theorem, we can say that the quadrilateral HIJK is a parallelogram.