Answer:
f(x) is linear
g(x) is exponential
Step-by-step explanation:
A linear function will always have the same rate of change between equally distant points, while an exponential function will have an increasingly large rate of change between equally distant points.
First, look at f(x). All these points are equally distant at 2 units apart on the x-axis, so they can be directly compared:

All of these points are the same distance apart on the y, so f(x) must be a linear function.
Now look at g(x). These are also all equally distant at only 1 unit apart.

These are very clearly not the same distance apart on the y, so g(x) must be the exponential function.
It will take 2 hours for 16 people to clear an acre of weeds, and 8 hours for 2 people to clear an acre of weeds.
100%/x%=20/15
(100/X)*x=20/15*x --I multiply both sides of the equation by X
100=1.33333333333*x --I divided both sides of the equation by .........................................(1.33333333333) to get X
100/1.33333333333=x
75=x
x=75
15 is 75% of 20
Substract 6 to both sides and you get 36 =-2d then you use the multiplicative inverse and d=-18.