Can you show a better photo some of the question is cut off
Total monthly rental is <span>$4,950</span>. ... Thus, total rental for one bed apartments is x*360 (=360x)
A parabola is a mirror-symmetrical U-shape.
- The equation of the parabola is

- The focus is

- The directrix is

- The axis of the symmetry of parabola is:

From the question, we have:


The equation of a parabola is:

Substitute the values of origin and vertex in 



Collect like terms

Solve for a

Substitute the values of a and the vertex in 

The focus of a parabola is:

Substitute the values of a and the vertex in 




The equation of the directrix is:

So, we have:
----- the directrix
The axis of symmetry is:

We have:

Expand

Expand


A quadratic function is represented as:

So, we have:


Recall that:

So, we have:


This gives


Hence, the axis of the symmetry of parabola is: 
Read more about parabola at:
brainly.com/question/21685473
Answer:
Problem 1) frequency: 160 heartbeats per minute, period= 0.00625 minutes (or 0.375 seconds)
Problem 2) Runner B has the smallest period
Problem 3) The sound propagates faster via a solid than via air, then the sound of the train will arrive faster via the rails.
Step-by-step explanation:
The frequency of the football player is 160 heartbeats per minute.
The period is (using the equation you showed above):

second problem:
Runner A does 200 loops in 60 minutes so his frequency is:
loops per minute
then the period is: 0.3 minutes (does one loop in 0.3 minutes)
the other runner does 200 loops in 65 minutes, so his frequency is:
loops per minute
then the period is:

Therefore runner B has the smaller period