2 to 5
Well it depends on how big your steps are but on average there are about 13 miles in 27963 steps.
A Chromatic scale starting from any of the 12 notes, in full, will have 13 half steps.
Using an average human step, there are about 422 steps in one tenth of a mile.
Here is the answer with Steps: 15x - 18 = -2x - 5 15x = -2x + 13 17x = 13 x = 13/17 x ~ .764705882