Answer:
Equation: 1=1
Length of the road after 16 days: 16 miles (if not adding to 53. if adding to 53, the answer is 69)
Explanation:
If they add one mile of road every day, its 1(mile) = 1(day.
Since its one mile every day, 16 days is 16 miles. Adding 53 + 16 = 69
