We were told that the taxi fare is $3.50 for the first mile and an additional S.50 for each mile after the first. Assuming that you ride x additional miles after the first, the total cost would be
3.5 + 0.5x
Given that you plan to give the driver a $3 tip for your 13-mile taxi ride, the equation representing the cost of the ride, c would be
Remember the cost of the first mile is $3.5. Since the total number of miles is 13, the number of dditional miles would be 13 - 1 = 12 miles. The equation would be
c = 3.5*1 + 0.5 * 12 + 3
= 3.5 + 6 + 3
= $12.5
The cost of the ride would be $12.5