Theorem
In a triangle, the measure of an exterior angle equals the sum of the measures of its two remote interior angles.
x + y = z
4n - 18 + n + 8 = 133 - 6n
5n - 10 = 133 - 6n
11n = 143
n = 13
z = 133 - 6n = 133 - 6(13) = 133 - 78 = 55
Answer: C. 55
Answer:
See below
Step-by-step explanation:
The initial ordered-pairs are 
We have a rotation of 90 degrees counterclockwise with respect to origin
Note. Previously the points were

After the rotation, we have

Thus, 
Then shifting horizontally to the right 2 units, we get ΔA'B'C'
Thus,

If the amount of time taken to go said distance is x and the amount of time taken to go back said distance is y, then the amount of miles total is 7x+3y due to that for every hour, she adds 7 miles when going there and 3 miles for walking back. In addition, since the total amount of time is 4 hours, x+y=4 as the total time spent as well as 7x=3y due to that they're the same distance.
x+y=4
7x=3y
Dividing the second equation by 7, we get x=3y/7. Plugging that into the first equation, we get 3y/7+y=4=10y/7 (since y=7y/7). Multiplying both sides by 7 and then dividing both by 10, we get 28/10=2.8=y in hours. Since 0.1 hours is 60/10=6 minutes, and 0.8/0.1=8, 6*8=48 minutes=0.8 hours, meaning that she should plan to spend 2 hours and 48 minutes walking back
For the division part:

But I think your question differs than this..
Am I right?
as your options do not include 1