1.
y = distance traveled
x = gallons of gas used
k = slope of the graph between distance traveled and gallons of gas used
slope is given as
k = 300 miles / 12 gallons
k = 25 miles/gallon
so the equation can be written as
y = 25 x
2.
given : y = 750 miles
using the equation
y = 25 x
inserting the values
750 = 25 x
x = 30 gallons
3.
c = cost per gallon = $3.75
c = total cost
Total cost is given as
Total cost = Cost per gallon x number of gallons
C = c x
C = $3.75 (30)
C = $112.5
