Given:
1 inch : 18 kilometers
Let us use the ratio and proportion method:
a:b = c:d where ad = bc
0.8 inches is <u>14.4 kilometers</u>
1 : 18 = 0.8 : x
x = 0.8 * 18
x = 14.4 km
1.4 inches is <u>25.2 kilometers</u>
1: 18 = 1.4 : x
x = 18 * 1.4
x = 25.2 km
2.1 inches is <u>37.8 kilometers</u>
1 : 18 = 2.1 : x
x = 18 * 2.1
x = 37.8 km
See photo. I hope it helps
Let
x--------> the number of children
y------> the number of teenagers
z------> the number of adults
we know that
------> equation A
-----> equation B

-------> equation C
Substitute equation C in equation A and equation B
![2[\frac{4}{3}y]+3y+5z=1,950](https://tex.z-dn.net/?f=2%5B%5Cfrac%7B4%7D%7B3%7Dy%5D%2B3y%2B5z%3D1%2C950)
--------> equation D
![[\frac{4}{3}y]+y+z=570](https://tex.z-dn.net/?f=%5B%5Cfrac%7B4%7D%7B3%7Dy%5D%2By%2Bz%3D570)
--------> equation E
Multiply equation E by 
--------> equation F
Adds equation D and equation F

therefore
<u>the answer is the option</u>

F(x) stands for a function, and if x stands for the number of days, than she can do 225 per day, which would be the multiplication to find the toatl 225x.
Then, with 45 extra, we add that to the equation:
F(x) = 225x + 45
Answer: F(x) = 225x + 45
Credit to: @2Educ8
+ = <3