casa corp. purchased a patent for $600,000 on january 1, 2007. the patent is being amortized over its remaining legal life of 15 years expiring on january 1, 2022. during 2011, casa determined that the appropriate estimate of the life of the economic benefits of the patent was 12 years from the date of acquisition. what amount should casa report in its balance sheet at december 30, 2011 for the patent, net of accumulated depreciation?