Answer:
A - one
Step-by-step explanation:
A typical demand curve, in economics, depicts the relationship between price of a commodity on the y-axis, and quantity demanded on the x-axis.
The demand curve obeys the Law of Demand, which states that the higher the price, the lower the quantity demanded of that commodity, and vice versa, all things being equal. Thus, a typical demand curve will slope downwards, from left to the right.
Therefore, line 1 indicates the demand curve.
Given:
The function that represents how the amount of fuel changes as a function of distance flown is

where x represents miles flown, and f(x) represents the amount of fuel remaining.
To find:
The rate of change for this scenario.
Solution:
The slope intercept form of a linear function is
...(i)
Where, m is the slope or rate of change and b is the y-intercept.
We have,
...(ii)
On comparing (i) and (ii), we get

Therefore, the rate of change for this scenario is -0.9. It means, the amount of fuel in the airplane is decreasing by 0.9 gallons per mile.

this formula is used to determine gpm (gallons per minute) of flow with a known hose diameter (d) and nozzle pressure (np). The constant (29.7) is consistent when figuring flow with in gallons with a know pressure expressed in psi (pounds per square inch).
Scenario example: a firefighter is using a handline to fight fire with an 1 3/4 inch line with a nozzle pressure of 100 psi. How much water is the firefighter flowing when fighting fire?
Use division or long division (ignore the decimal point)
Then put the decimal in the same spot as the dividend (the number being divided)
1/10, 3/10, 0.9
Hope this Helps