GHI Corporation purchased a building for $600,000 on January 1st, 2023. The building has an estimated useful life of 40 years and a residual value of $50,000. Calculate: a) Annual

straight-line depreciation expense. b) Accumulated depreciation at the end of the fourth year. c) Book value of the building at the end of the sixth year. d) Journal entry to record depreciation expense for the first year.