Let x represent the cost per gallon of gasoline.
Let y or f(x) represent the cost of x gallons of gasoline.
Given that the cost per gallon is $2.79,
The function would be
f(x) = 2.79x
The domain refers to all possible values of x that can fit into the function. Given that the truck holds a maximum of 28 gallons, the maximum value of x is 28. When the truck is empty, the minimum value of x is 0. Therefore, the domain is 0 to 28
The range refers to all possibel values of y or f(x) that can satisfy the function.
When x = 0, f(x) = 2.79 * 0 = 0
When x = 28, f(x) = 2.79 * 28 = 78.12
The range would be 0 to 78.12
Domain: 0 to 28
Range: 0 t0 78.12