During 2016. Riverbed Corporation spent $162.720 in research and development costs. As a result, a new product called the New Age Piano was patented. The patent was obtained on October 1, 2016, and had a legal life of 20 years and a useful life of 10 years. Legal costs of $36,720 related to the patent were incurred as of October 1, 2016. Prepare all journal entries required in 2016 and 2017 as a result of the transactions above. (Credit account titles are automatically indented when amount is entered. Do not indent manually. If no entry is required, select "No Entry for the account titles and enter for the amounts) Date Account Titles and Explanation Debit Credit 2016 (To record research and development expenses) 2016 (To record legal expenses) 2016 (To record amortization expense) 2017 On June 1, 2018, Riverbed spent $8.280 to successfully prosecute a patent infringement suit. As a result, the estimate of useful life was extended to 12 years from June 1. 2018. Prepare all journal entries required in 2018 and 2019. (Credit account titles are automatically indented when amount is entered. Do not indent manually. If no entry is required, select "No Entry for the account titles and enter for the amounts.) Date Account Titles and Explanation Debit Credit 2018 (To record patents) 2018 (To record amortization expense) 2019 In 2020, Riverbed determined that a competitor's product would make the New Age Piano obsolete and the patent worthless by December 31, 2021. Prepare all journal entries required in 2020 and 2021. (Credit account titles are automatically indented when amount is entered. Do not indent manually. If no entry is required, select "No Entry for the account titles and enter for the amounts.) Account Titles and Explanation Debit Credit