Compute amortization expense. (LO 4), AN These are selected 2017 transactions for Wyle Corporation: Jan. 1 Purchased a copyright for $120,000. The copyright has a useful life of 6 years and a remaining legal life of 30 years. Mar. 1 Purchased a patent with an estimated useful life of 4 years and a legal life of 20 years for $54,000. Sept. 1 Purchased a small company and recorded goodwill of $150,000. Its useful life is indefinite.