So what is the question ?
G(6)-g(2)/6-2
g(6) = 50
g(2) = 14
50-14/6-2
36/4
=9
It would take 2 hours. To complete the whole lawn you would need:

To make a whole, so to get that we multiply:

So we use the same number required for the whole lawn, and multiply it times the hours
A: Speed is Independent as it can be anything with no restrictions. Gas mileage is dependent as it relies on the value of speed for its value to be decided.
B: The first letter of speed is "S" so it can represent the variable. The first letter of mileage is "M" so the variable can be represented by that letter. It really can be any letter.
C: no context
D: no context