Help with coordinate plains?

Tallahee was established as the capitol of Florida because it was between Pensacola and St. Augustine. The distance from Pensacola to Tallahee can be represented as (9x+30) miles. The distance from Tallahee to St. Augustine can be represented as (11x+5) miles. The distance from Pensacola to St. Augustine is 395 miles. Is Tallahee the midpoint of Pensacola and St. Augustine? Show your work to support your conclusion.