Given that the function y=3.5x+2.8 represents the cost y (in dollars) of a taxi ride of x miles, and that you have enough money to travel at most 20 miles.
The domain of a function is the set of possible values of x, given that the maximum number of miles you can travel is 20 miles, the domain of the function is from 0 to 20.
Domain = {x: 0 ≤ x ≤ 20}
The range of a function is the set of the possible values of the function.
For x = 0, y = 3.5(0) + 2.8 = 2.8
For x = 20, y = 3.5(20) + 2.8 = 72.8
Therefore, the range of the function is from $2.8 when no mile was covered and $72.8 when 20 miles was covered.
Therefore, range = {y: 2.8 ≤ y ≤ 72.8}