Answer:
Natalia's work is wrong.
Step-by-step explanation:
Natalia divided a decimal number by an entire number. Since division is a operation derived from multiplication, the best approach to check if work was good is multiplying the given result by denomination, that is:
1) 
Given.
2) 
Definition of addition.
3) 
Distributive property.
4) 
Definitions of multiplication and decimal number.
5) ![x = 72 +[2\cdot (10)^{-1}]\cdot 12](https://tex.z-dn.net/?f=x%20%3D%2072%20%2B%5B2%5Ccdot%20%2810%29%5E%7B-1%7D%5D%5Ccdot%2012)
Definition of division/Associative property.
6) ![x = 72 + [2\cdot 12]\cdot (10)^{-1}](https://tex.z-dn.net/?f=x%20%3D%2072%20%2B%20%5B2%5Ccdot%2012%5D%5Ccdot%20%2810%29%5E%7B-1%7D)
Associative property.
7) 
Definition of multiplication.
8) 
Definition of divsion.
9) 
Defintion of decimal number.
10) 
Definition of addition/Result
Natalia's work is wrong.
I’m not entirely sure but the answer might be 72 1/2 miles. I added up 12 1/3, 8 3/4, 17 2/8, 23 2/3, and 10 5/10. And I got 72 1/2.
Alright, lets get started.
At the beginning of her training, she is able to run 2 miles without stopping means 2 will be in the addition when we will write the equation for her running miles.
Her goal is to increase her distance by three quarters of a mile each week.
Means in first week, she will add the distance = 
miles
Suppose she runs x weeks, so shee will add distance = 
So, suppose she runs total number of miles = d, then
Where d is total numer of miles she runs
x is number of weeks : Answer
Hope it will help :)
The answer is A. 4(n 3) - 6n
