The fare rate for x miles is:
[tex]x^2-5x[/tex]
and there is a base fare, which means that even for zero miles, the user have to pay "4". Hence the total cost for a ride of x miles is the fare rate plus the base fare:
[tex]x^2-5x+4[/tex]
Hence the answer is the last option, x^2-5x+4
