please explain in detail how to solve this . thank you

Your answer is correct. Two independent companies, Bonita Co. and Carla Vista Co., are in the home building business. Each owns a tract of land held for development, but each would prefer to build on the other's land. They agree to exchange their land. An appraiser was hired, and from her report and the companies' records, the following information was obtained: Cost and book value Fair value based upon appraisal Bonita's Land $578700 810000 Carla Vista's Land $289800 635400 The exchange was made, and based on the difference in appraised fair values, Carla Vista paid $174600 to Bonita. The exchange lacked commercial substance. For financial reporting purposes, Bonita should recognize a pre-tax gain on this exchange of